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Bob Frazier's Music Page
Music Theory Chapter
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A long time ago, in a galaxy far away, I had NO concept of why music worked, why chords were formed the way they are, and so on. I looked in libraries and tried to find the information that I wanted, but nearly everything was oriented on spending years in school taking some class that I had absolutely no time for, because of one thing or another. Then, I stumbled on a rather concise book written by a guy named "Bugs Bower", a horn player, called "Chords and Progressions", which had everything laid out in a rather straightforward manner. I found THIS to be what I was looking for. Incidentally, it was being used by Joe Marillo, a local San Diego musician (sax player), to teach theory to his students. So, for those who want to know the basics of music theory, without going through a lot of 'garbage' to get the information, it's all here. All of it. Well, most of it, anyway.

NOTE: this site is old. I try to keep it up to date, but you may occasionally see some VERY old references in here to things that are more 2 decades old. OK maybe that stuff no longer applies, but the general concepts are still good.

Modern music, derived from the music of the European Rennaissance, is based on a 12-note scale that is formed logarithmically. Each octave doubles the pitch (or frequency) of the previous octave. It is the way in which we hear the sounds with our ears, so naturally our music reflects the same 'logarithmic' pattern. Each note in the scale can therefore be formed by increasing the pitch (multiplying its frequency) of the previous note by the 12th root of 2, and the difference between 2 notes in the 12-note scale is referred to as a 'half step'. OK, in English: The standard 12-note scale defines 'A' at 440Hz, or 440 cycles per second. 'A' at the next octave up would be 880Hz, and the next octave up would be 1760 Hz. About half-way (in pitch) between 'A' and the next 'A' is 'E', which happens to be the '5' note in the scale, and is also the 8th 'half step' (more on this later). It's frequency is approximately 660Hz (though not exactly). These two notes, 'A' and 'E', form the basis of most of the 'A' chords, because the mixture of the two tones of 'A' (440 Hz) and 'E' (660 Hz) form a 'sum' and 'difference' set of frequencies at 220Hz (also an 'A'), and 1100Hz (5 times the 'A' one octave below), both of which are frequency multiples of 'A'. It should be worth noting that it is the relationship between the frequencies of the various notes which give each chord its tonal qualities, and those notes which form sum and difference frequencies that are multiples of the 'fundamental' note for the chord are considered to be most pleasing to the ear.
Fortunately, nobody is going to make you sit down with a calculator and determine which notes form pleasant frequency combinations. Rather, let's rely on the work done by centuries of musicians (some famous, some not) and music theoreticians, and provide a list of these valid combinations.

Of important note: though other scales exist, such as that used by Chinese classical music, or Middle-Eastern music, the focus of this page is on the 'European Rennaissance' 12-note scales. I have already received one e-mail reminding me of this, so I have taken the effort to distinguish which scale I am referring to, while at the same time edifying others who may not be aware that other musical scales exist.

The 12-note MAJOR scale follows the pattern indicated below:

    whole step, whole step, half step, whole step, whole step, whole step, half step

This forms a full 8-note "octave", consisting of 7 notes plus the first note at the next highest pitch.

An example of this is the 'C' scale, which consists of 'C, D, E, F, G, A, and B', plus 'C' again at the next highest octave. By convention, each note in the scale is referred to by number, such that the 'C' would be the '1' note in the 'C' scale, the 'D' the '2' note, the 'E' the '3' note, and so on. This is how various chords are named, so that a 6th chord contains the '6' note, and so forth. For some chords this continues on into the next octave, such as a '9' or a '13' chord, and by convention some extra notes may be thrown in to make it sound nice (as with the '9' chord), generally a flatted (or dominant) 7.

Other scales also exist (minor, whole-tone, etc.) but can usually be expressed in terms of one of the major scales, with sharps or flats added in appropriate places. The major scale, though, corresponds with the 'do re mi' notes that we are all so familiar with, and forms the basis of the other scales.

Incidentally, if you are not already aware, a 'sharp' note merely adds a half step to a note. The notes in the 'C' scale have no sharps or flats in their names, and correspond to the white keys on a modern piano (some really old pianos have mostly black keys, contrary to modern ones). Other scales, beginning with notes other than 'C', can be formed by starting on the appropriate note, and using the 'whole step whole step half step whole step whole step whole step half step' pattern to form the scale, thus adding a 'sharp' or 'flat' to the appropriate notes to form the scale, according to a few rules (indicated below):

1. Each letter (A through G) must be represented once, and once only, in the scale
2. All sharped or flatted notes must either be all sharped, or all flatted
3. Double-flats and double-sharps are assigned when necessary, as with the 'F flat' scale.
4. Each major scale has a unique number of sharps/flats assigned to it, and the order of the sharps or flats follows the cycle of 5th's (more on this later).

OK - those of you who already know something about music theory: Since F has one flat, and B-flat has two flats, and F-flat has 8 flats (the 'B' is double-flat), what has 17 flats?

Answer: An 18-wheeler with one good tire.... :)

In a nutshell, the following is a list of each major scale, and the appropriate number of sharps or flats that it uses, in their appropriate 'cycle of 5th' order:

• C - none
• C# - 7 sharps: F#, C#, G#, D#, A#, E#, B#
• Db - 5 flats: Bb, Eb, Ab, Db, Gb (same note as C#, incidentally)
• D - 2 sharps: F#, C# (note D has 2 sharps, Db has 5 flats, 5 + 2 = 7)
• D# - 9 sharps: F##, C##, G#, D#, A#, E#, B# (note 'D' has 2 sharps, plus 7 sharps = 9 sharps, and it's the same note as Eb for all practical purposes)
• Eb - 3 flats: Bb, Eb, Ab (note that 'E' is a 3 reversed, for 3 flats)
• E - 4 sharps: F#, C#, G#, D# (note that 'E' has 4 lines in it, for 4 sharps)
• F - 1 flat: Bb
• F# - 6 sharps: F#, C#, G#, D#, A#, E# (6 sharps for F# plus 1 flat for F = 7 ... see the pattern?)
• Gb - 6 flats: Bb, Eb, Ab, Db, Gb, Cb
• G - 1 sharp: F# (for G#, just sharp everything once and double-sharp the F)
• Ab - 4 flats: Bb, Eb, Ab, Db (the 'A' looks a little like a 4)
• A - 3 sharps: F#, C#, G# (the 'A' has 3 lines in it)
• Bb - 2 flats: Bb, Eb
• B - 5 sharps: F#, C#, G#, D#, A#

Incidentally, some musicians will denote a key (major scale) by indicating the number of sharps or flats that it has with the number of fingers pointed up (sharps) or down (flats). In other words, 3 fingers down means key of Eb, a really nice key for alto sax players. So, next time you see a piano player or band leader point 3 fingers at the floor right before beginning a song, you'll know why...

• Harmonic minor: flat the 3rd and 6th notes in the scale. Note that the key signature flats the 3rd, 6th, and 7th notes (see 'Natural minor', below).
• Natural minor: Similar to harmonic minor, but the 7th note in the scale is also flatted.
• Melodic minor: flat the 3rd note in the scale on the way UP (increasing pitch), but flat the 7th, 6th, and 3rd on the way DOWN (decreasing).

A discussion of minor scales and major scales, leads us right into CHORD FORMATION. The following is a brief list of all of the basic chords, and the notes that form them.

• Major chord: 1st, 3rd, 5th note in the scale. Example: C major: C, E, G
• Minor chord: 1st, flat 3rd, 5th note in scale. Example: C minor: C, Eb, G
• Minor 7 chord: 1, 3b, 5, 7b notes in scale. Example: C minor 7: C, Eb, G, Bb
• Major 7 chord: 1, 3, 5, 7 notes in scale. Example: C major 7: C, E, G, B
• Dominant 7 chord: 1, 3, 5, 7b notes in scale. Example C Dom 7 (or C7): C, E, G, Bb
• Diminished chord: 1, 3b, 5b, 6 notes in scale. Example: C Dim: C, Eb, Gb, A
• Augmented chord: 1, 3, 5# notes in scale. Example: C Aug: C, E, G#
• Major 9 chord: 1, 3, 5, 7, 9 (or 2) notes. Example: C Maj 9: C, D, E, G, B
• Minor 9 chord: 1, 3b, 5, 7b, 9 (or 2) notes. Example: C minor 9: C, D, Eb, G, Bb
  NOTE: to voice this in a 'blues' style, the 'D' should be in the next octave. To voice this as a 'cluster chord' (dissonance), the 'D' should be in the same octave. Each has its own effect on the sound, which is dramatic in the case of the minor 9. Voicing of chords will be discussed later on...
  
• Dominant 9 chord: 1, 3, 5, 7b, 9 (or 2) notes. Example: C Dom 9 (or C9): C, D, E, G, Bb
• '2' chord: 1, 2, 3, 5 notes. Example: C2: C, D, E, G
• 6th chord: 1, 3, 5, 6 notes. Example: C6: C, E, G, A
• 6-9 chord: 1, 3, 5, 6, 9 (or 2) notes. Example: C 6-9: C, D, E, G, A
• suspended chord (or 4 chord): 1, 4, 5 notes. Example: C sus: C, F, G
• Dominant 11th chord: 1, 3, 5, 7b, 11 (or 4) notes. Example: C Dom 11 (or C11): C, E, F, G, Bb
• Major 11 chord: 1, 3, 5, 7, 11 (or 4) notes. Example: C Maj 11: C, E, F, G, B
  NOTE: With regard to voicing, chords like this are best spread over several octaves
  
• Minor 11 chord: 1, 3b, 5, 7b, 11 (or 4) notes. Example: C minor 11: C, Eb, F, G, Bb
• 13th chords: Like the '7' chords (above), but add a '6' note. Example: C13: C, E, G, A, Bb

Other chords also exist, and follow some simple rules. Basically, any numbers following the letter indicate additional notes other than the standard ones. A 'Maj' in front of a number indicates that the 7 is not flatted for this chord. A 'Dom' (or no 'Maj') indicates that the 7 *is* flatted. A 'Minor' chord has a flatted 3 note, and always a flatted 7 (when present). 'Sus' chords use a 4 in place of the 3, 'Dim' chords use a flatted 3 and flatted 5, and 'Aug' chords use a sharped 5.

Confused yet? Wait... there's more! Go get a soda, sit down, relax, and then come back if your brain is hurting right now. Let some of this stuff get absorbed, because it gets better. Trust me.

Normally, when playing a song in a particular scale (or key), you will find that certain chords are nearly always used. Not always, but nearly always. The notes within the key form certain chords without the need to add extra sharps or flats. Below is a list of the chords, the relative position within the key, and the technical term (for those who want to know). This example will be using the key of 'C', because it's simpler to see on a piano keyboard. NOTE: Roman numerals are used to denote the chords, as opposed to Arabic numerals for notes.

• I - Tonic - C Major, C Major 6, C major 7
• II - Supertonic - D minor, D minor 7
• III - Mediant - E minor, E minor 7
• IV - Subdominant - F Major (often an F6, occasionally an F major 7)
• V - Dominant - G or G 7 (almost always a G7)
• VI - Submediant - A minor or A minor 7 (usually A minor 7)
• VII - Leading Tone - B diminished

For sharps, it's similar:

    B, E, A, D, G, C (or B#), F (or E#), A#, D#, G#, C#, F#, B, etc.

As an exercise, on YOUR instrument try playing these notes as major chords, in the 'cycle of 5ths' order, and you will probably get a better perspective on where the cycle of 5ths comes from and why it exists. Essentially, the chords represent a natural progression from one chord to another, that you can find in many many places. In fact, one of my favorite 'bridges' within a blues or jazz song goes something like this (in the key of 'C'):

    F6, F minor 7, E minor 7, A minor 7, D minor 7 (or D minor 9), G7, C6

The F6 to F minor 7 is a half-step alteration of 2 notes, the 3 to a 3b, and the 6 to a 7b. The E minor 7 just happens to contain the same notes as a C major 9, minus the 'C', which (essentially) means that a shift from an F minor 7 to to an E minor 7 is similar to a shift from 'F' back to 'C' (cycle of 5ths). Then, using the E minor 7, the next chord FORWARD in the cycle of 5ths would be 'A something', or in this case an A minor 7, followed by D minor 7 (next in cycle of 5ths), G 7 (next in cycle of 5ths), and finally C6 (the 'I' chord, or Tonic). Since the E minor 7 is really a substitue for C6 (more on this later) you can really keep this going indefinitely, or until the audience gets tired of hearing it, by going from the G7 back to an E minor 7, and continuing something like this:

    F6, F minor 7, |: E minor 7, A minor 7, D minor 7 (or D minor 9), G7 :|, C6
    (the '|:' represents opening repeat, and ':|' ending repeat for this example)

And, if you wish to make an entire song out of this (in blues style), you could use chords something like THIS in the key of 'C':

(now doesn't that beat a 3-chord special, with C, F, and G?)

On a 'Jazzier' note, there's also the '2,5,1' straight-ahead progression. Using chord substition (hinted at in the previous section), this can become rather complex. Basically, a substitute chord will contain 2 or more notes from another chord that defines the sound of the chord you are substituting for. Even though certain notes have been omitted, or substituted with notes belonging to the substitute chord, the basic sound still remains. This is especially useful if you are trying to follow a 'cycle of 5ths' while remaining within the key (as in the example above). But, often the chord substitution is used to add 'color' to a song, while not deviating from a particular pattern of chords, such as the '2,5,1' progression. As an example:

The II chord in the '2,5,1' progression is the D minor 7, the V chord is the G7, and the I chord is the C major 7. Alternate to the 'I' chord is E minor 7, and A minor 7 (which together follow the cycle of fifths back to the II chord). By substituting these 2 chords for the C major 7, a definite variety and sense of "progression" is added that wouldn't have been there before. In addition, I went ahead and added an F major 7, which (by the way) substitutes for the D minor 7 'II' chord. The F major 7 to F minor 9 progression leads into the E minor 7 (as before), then follows the cycle of fifths back to the 'I' chord. Elementary, my dear Thelonias!

Typical substitute chords

The following is a 'short list' of possible substitute chords. The basic principle is that certain notes in common to both form the sound, and I'll try to indicate which notes are common in each case (but please bear with me in case of error).

• C major, major 7, or C2: E minor or E minor 7 (III chord); common E, G
• C6, C13: A minor 7 (VI chord); common A, C, E, G (exact same notes as C6)
  Because the C6 and A minor 7 share the same notes, the chord change depends upon the note which has been placed on the bass (see 'chord voicing', below). Therefore, an A minor 7 is like a C6 with an 'A' as its lowest note, or C6/A. Many songs use a C6 to A minor 7 transition (50's rock & roll 'ballads' being a prime example).
• C7 or C9: Bb 9 (common Bb, C, combined with 'Dom 7' sound; adds 'suspense')
• C7: Gb7 (common E and Bb) - connects well from C6 to an 'F' (I to IV transition)
• C9: G minor 6 (common G, Bb, D) - works well in reverse, also
• C minor 6: F9 (like above, but reversed) (common G, C, Eb)
• C minor 9: Eb major 7 (common D, Eb, G, Bb). Eb maj 7 with 'C' on bass plays as a C minor 9
• C 11 or C sus: Bb 9 (common Bb, C, F). Bb 9 with 'C' on the bass plays as a C11 or C sus 4 with color

• standard form: C, E, G
• 1st inversion: E, G, C
• 2nd inversion: G, C, E

    C major: C, E, G ('C' on bass one octave below)
    C major: C, E, G ('E' on bass one octave below) (can be written as C/E)
    F major: C, F, A ('F' on the bass one octave below).

The chord change itself left one note the same (the low 'C' in the chord). On a piano, the left hand might 'octave' the bass note for this example, adding a great emphasis to its effect on the chords. (I am intentionally NOT placing a score here, because I'm trying to help you think of the chord formation in terms of the theory, and NOT in terms of the mechanics). By leaving one note the same, playing a 2nd inversion on the chord, you not only add the 'suspense' following the chord change, but you minimize the amount of change required to play the new chord. 2 notes change by one whole step, one does not change. The bass line progresses from C to E to F, a natural 'upward moving' change. Aside from its use in Jazz, Tchaikovsky often used progressive changes like this (as well as the use of 2nd inversion to create suspense) in his music. Listen carefully to the 'Waltz' from Swan Lake for a perfect example - how long does he hold that V chord??? Just long enough to put you on the edge of your seat!

Additional concepts in voicing involve the use of 'cluster' chords (chords in which all of the notes appear close together), which often creates a sense of dissonance, and is often used in Jazz music, or the 'spreading' of a chord across several octaves (either on a piano, or in an orchestra). Often, the bass clef is far too low to place notes like 1, 3, and 5 close to one another. However, you CAN create an 'octaving' effect (essentially, 1 and 8), or use 1 and 5, or 3 and 8 together. Playing a 'C' chord on the left hand on a piano ('standard form') can therefore use C and G and still sound ok, or use an E and the 'C' above it (1st inversion) and sound 'ok'. The remainder of the chord can then be spread across 3 octaves by doing a 'stretch' between the left and right hands. Incidentally, this works very well for a minor 9 chord, which tends to sound rather 'cluttered' when played within a single octave; however, playing the 'D' note as the HIGHEST note in a C minor 9 (across 3 octaves) adds a real 'jazzy' sound, and makes a nice ending chord for a blues song (as in the Windows 95 Blues).

Often time, to avoid repetition and boredom in an otherwise 'hit' song, you can add a 'bridge' somewhere in the middle of it that differs significantly enough from the rest of the song, though similar enough as not to detract from the continuity provided in the rest of it. A good example of this is found in The 80's Forever, where I repeat the main section twice, do one 'bridge', go back to the main section, another bridge, and a final repeat of the main section again. Though a lot of repeating occurs, it no longer sounds 'repetitious' due to the existence of the 'bridge'.

Typicall, a 'bridge' section involves some kind of key change, though not so dramatic that you need to change the key signature on the score (if you even bother to write it down on sheet music... "Hey, look everyone, this guy can actually read the notes"). Typically, you'll just run up the cycle of fifths to the 'IV' chord in the current scale (example: if you WERE in 'C', then the bridge is (effectively) in 'F'). Naturally you'll need a "cool" way of transitioning back to the I chord (generally a cycle of 5ths transition). It always helps me to consider what this chord is before I write the 'bridge'; that way, I can plan how to 'get back' before I get to the point where I have to 'get back'.

So, if you are in the key of 'C', you'll need the 'V' chord in the scale (or a substitute of it) to get back to the 'C' again. This means you'll here a 'G', or a substitute of a 'G' chord, at the end of your bridge. In this case, a G minor is adequate, though not preferred. A typical substitute of a G minor 7, however, would be a Bb6 or Bb6-9, as they have the common Bb, D, and F... in fact, you could also substitute a Bb6-9 chord for an F11, making it possible to transition TO the Bb6-9 from the C using the same cycle of 5ths. Incidentally, this idea makes it possible to alternate between 2 chords that are 1 whole step apart, an effective echnique to employ in a bridge if you lack any particular ideas. So, for a song in 'C', you might have a bridge like THIS:

    F, Eb, F, Eb, F, Eb, F, G, C

And, to avoid repition, use substitute chords, like this:

    F, Eb, D minor 7, G minor, A minor, Bb, F, G, C
    (so I cheated a little on the Bb - whatever)

Of all of the possible 'bridge' sequences, though, the one I like the best is what I would call the "How High The Moon" progression. Those of you who've ever heard this song probably know what I'm talking about. The song "How High The Moon" is a Jazz standard that employs a set of chromatic key changes (each time going down by a whole step) by a rather creative use of the cycle of 5th's. The chord progression goes something like this (beginning in the key of 'E'):

    E, E minor, A, D, D minor, G, C ...

Without displaying the entire song (or enduring the criticism should I get one or more chords wrong while attempting to transcribe from memory) I think the above example is sufficient in illustrating what I mean by a "How High The Moon" progression. Basically, starting with the I chord in the current key, you transition to the VIIb using the following sequence:

    I, I minor, IV, VIIb

The VIIb now becomes the 'I' chord in the next series. Typically, as a 'bridge', the progression will actually start from the IV chord in the original key, so that if your song is in 'C', the 'I' chord for this progression would begin with the 'IV' chord in the key of 'C', in this case an 'F'. You can then repeat this basic progression a couple of times, then transition back to the original key using the 'V' chord in the original key as the final transition chord (in this case, a 'G'). Now that you've been completely confused, I'll give you an example, starting with a simple song in the key of 'C':

    C, F, G, C, C7, F, F minor, Bb, Eb, Eb minor, Ab, Db, Db minor, Gb, G, C

Although there are probably BETTER and more creative ways of getting back to a 'G' from somewhere within this progression, a half-step upward progression is acceptable, going from the Gb to the G. Ideally, though you'd use some kind of substitute chord that did a cycle of 5th's transition to the G. Since 'D' transitions to G, a substitute of D (including minors) might be: F, F# minor (or Gb minor), Bb, B minor, and so on.

You can apply a few basic principles for transitions, substitutions, and the infamous "what chord do I play next" question when improvising or composing. Some of these are:

• Cycle of 5ths - never forget that the natural progression of one chord to another follows the cycle of 5ths.
• 2 or more 'Common Tones' - use a chord that shares 2 or more 'common tones' with the previous chord. Major to minor, adding a dominant 7, or a true 'substitution' of one chord for another generally apply this concept to get a 'sound-alike' chord that doesn't sound EXACTLY like the other. In essence, either the 1 and 3 notes in the chord, or the 1 and 5 notes, or (occasionally) the dominant (flat) 7 and 1 or 3 notes must remain the same in order to obtain the same 'sound' as before, but be different enough to 'change'.
• Major to Minor - this is a simple transition that implies a substitute for the minor, which can often lead you to a new key if you want to 'modulate'.
• Chromatic - a half step or whole step up (depending upon where you are in the scale) is another one of those 'natural progressions'. Without going into detail, substituting the appropriate chord from the cycle of fifths, then doing a simple substitution, results in a whole step 'chromatic' progression. The half step is simply another 'natural' progression you can make use of, like II,I#maj7,I (where the I#maj7 is actually a substitute for the V, making it a II,V,I progression - and where have I heard THAT one before?
• Diminished and Augmented - typically used 'in between', an Augmented chord (sharp 5) progresses into the next chord in the cycle of fifths, whereas a diminished chord progresses chromatically by a half step in either direction. The Beatles used Augmented chords (sometimes called 'German 6th') a LOT in their earlier music. A typical progression MIGHT be G, G+, C, C-, G, illustrating the effect the augment chord has, plus the 'common tone' aspect of the C minor, which shares 2 common tones with the G+.
• Chromatic notes - and the previous example, G, G+, C, C-, G demonstrates this one as well. The 'D' goes to a 'D#' in G+, followed by 'E' in the 'C', followed by D# (Eb) in the C-, and back to 'D' again. Playing the chord sequence emphasizes this note going up 2 half steps and back down 2 half steps, and it forms a sort of 'chord melody'. The 'highest' note in a chord typically generates the chord's melody, though often the 3 or 5 note within the chord will also 'dominate' the sound, particularly if you are using it in a 'chromatic note' progression.

In Space Thriller I did a sequence similar to this for the bridge, ending up on the V chord for 2 measures, and not enough space to do anything else. So, I ended up doing my transition as a set of chord inversions, which gave the impression of an increasing pitch, since the highest pitched note in a chord makes the 'melody' sound that you often hear when only chords are played. Basically, I did a 2nd inversion Gb chord (3 note is highest note), followed by a G4 (same inversion) (4 note is highest note), followed by a 'Standard Form' Gb (5 note is highest note), followed by a Gb Augmented chord (which sharps the 5 note, increasing its pitch by a half step). This caused the effective melody to progress as 3, 4, 5, 5#, which then took 2 measures of the same chord and built a 'suspense' effect into it. A Gb4 chord is like a 'Gb suspended' chord except that it typically also contains the 3 note, for a different effect on the sound. As well, Gb is also the V chord in the Bb scale, which creates a suspense effect in and of itself (as in Swan Lake, example noted above). Also, a chromatic upward progression causes a 'suspense' effect, and the final 'augmented' version of Gb is 'suspense' implying progression to the next chord. So, instead of having 2 measures of Gb sound 'boring', it effectively puts you in a state of 'suspense', building a nice progression back into the main 'movement' (after all, it IS a classical piece).

Often times a chord will be denoted using a 'shorthand' form. I have avoided using this form up until now because its use tends to make the writing more confusing, and people would likely be referring back to the shorthand, rather than just reading the long descriptions of the chords. So, I'll summarize the shorthand usage below:

• Major: letter by itself, as in 'C' for C major
• Minor: letter followed by '-', as in 'C-' for C minor
• Major 7: Letter followed by 'maj7' or a 7 with a line through it, or a triangle as 'C maj7'
• Minor 7: letter followed by '-7', as in 'C-7' (this also extends to other chords)
• Augment: letter followed by a '+', as in C+ for C augmented
• Suspended: letter followed by '4' or 'sus' or 'sus4', as in 'C sus'
• Diminished: letter followed by 'dim' or a circle, as in 'C dim'

Therefore, a chord progression as follows

could also be expressed as follows:

But, one of the greatest obstacles to overcome is the fact that computerized music often sounds "too perfect". It is an interesting paradox that music that is 'perfect' (i.e. all instruments perfectly in tune, all in perfect time sequence with each other and the musical score) sounds less appealing than music that has slight imperfections. This is especially true with large orchestras, for it is the IMPERFECTIONS that give it the characteristic "large orchestra" sound.

I call this effect, the "Uncanny Mountain". I derive it from the term Uncanny Valley, a term often used in robotics and CG. It's related to how 'human' a robot or computer-generated character looks and acts, and how willing people are to accept it. A robot that's "not quite human" may cause people to react with revulsion, whereas the same people would be willing to accept a robot that's either LESS human, or MORE human, but not THAT one, because it's within the 'Uncanny Valley'.

This 'Uncanny Mountain' (inverted 'Uncanny Valley') effect applies the same with human voices as with instruments. The sound of many 'close to perfect' voices form a 'choir' sound, or multiple strings on an instrument form a 'piano' sound, or the sound of a 12-string guitar, or an ensemble. It differs greatly from the sound of a soloist, even if the choir (or ensemble) is singing (or playing) the exact same note! Some of the MIDI patches have attempted to compensate (certain string and brass patches) using an electronic chorus or slightly detuned VCOs, but the overall effect of such enhancements isn't always what is desired. And the slight uneven pitch of a good soloist is actually PREFERABLE to something that is 'too perfect', which is one reason why I despise 'Auto-Tune'.

So, within a couple of the MIDI files that I've created, I've 'de-tuned' some of the instruments, and played them in unison. The results have been very effective in creating a 'big band' or 'orchestra' sound, where without 'de-tuning' any instruments, all voices play exactly the same frequency, and you cannot tell the difference between 1 instrument and 5 instruments playing the same note. The 'de-tuning' effectively inserts an 'imperfection' into the music, but the music sounds better as a result of it. In my case, I used a static de-tuning, specified by a constant 'pitch bend' factor, some sharp and some flat, with approximately equal numbers of instruments on either side of 'zero'. Additionally, in one of them I effectively inserted very short (1/128th, 1/64th, 3/128th, etc.) rests at the beginning of certain tracks (each having a slightly different 'initial rest') to delay its starting slightly, and thereby simulate the natural timing imperfections of multiple musicians in a large orchestra (I could have also appropriately lengthened or shortened certain notes, but it would make the scores look ugly).

Apparently there is an existing term for this: 'HUMANIZING', where you add slight detuning and/or timing imperfections in order to make the MIDI replay sound 'less robotic' and 'more human'.

As an example I used a MIDI file in which I had a large brass orchestra, with everything 'properly quantized' and in tune, for the first 25 seconds of audio. Then I used the same MIDI file, but with some simple timing and tuning imperfections added in for the next 25 seconds. Finally, I did the 'imperfect' MIDI file a third time, but with chorus and reverb enabled.
The results can be heard here

Obviously, an orchestra sounds VERY BAD when the 'imperfections' are too great. One or more instruments grossly out of time, or grossly out of tune, sticks out like a sore thumb and severely detracts from the remainder of the orchestra. I certainly wouldn't want to be THAT musician (even though woodwind players can always blame a 'cracked reed' if they want to). Yet, unless an infinitesimally small imperfection is present, the orchestra won't sound right either. Fortunately, the physics of the instruments themselves, and the inability of people to tune them PERFECTLY within 6 decimal places of accuracy, automatically cause the necessary imperfections to occur.

For those of you who would like to know, most synthesizers and sound fonts map GENERAL MIDI channel #10 as percussion. This includes how Windows operating systems and programs like Fluidsynth and Timidity invoke the correct wave tables for drum sounds. So, by using MIDI channel 10 you can invoke various drum sounds by playing particular notes to this MIDI channel. The actual mapping of the individual notes to a particular drum sound was unknown to me, back in the day, until I purchased a wave table card and began experimenting to find out how to create the 'drum sounds' that most of the sample MIDI files had in them. Then, with additional information (over time) I produced a chart, which you may find useful if you use a note-based MIDI sequence application (like "The NoteWorthy Composer"). You can view or download this 'percussion mapping' chart (text only) by mousing-clicking HERE.