ABC Music Notation: Chords

by John Chambers
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There are two fundamentally different way of dealing with chords:
  • Accompaniment chords written above or below the staff.
  • Multiple-note chords played by a single instrument. We will deal with these separately here, since they are written differently in ABC (and in most standard music notation).

    Accompaniment or "guitar" chords

    Chords to accompany the melody, i.e., accompaniment chords (termed 'guitar chords' in the previous abc standard) can be included. Depending on the package, accompaniment chords will be displayed either above or below the melody line. Some playback packages can play accompaniment chords.

    An accompaniment chord is enclosed in double-quotation marks. It is placed to the left of the note it is sounded with, without an intervening space, e.g., "Am7"A2D2.

    The chord has the format <note><accidental><type>/<bass>, where <note> can be A-G, <accidental> can be b, #, or nothing, <type> is the type of chord, and /<bass> is an optional bass note.

    Valid chord types are:

    m or min minor
    maj major
    dim diminished
    aug or + augmented
    sus suspended
    7, 9 ... 7th, 9th, etc.

    The chord type can be combined, e.g., Cdim7. And, obviously, maj can be (and usually is) omitted.

    A slash after the chord type is used only if the optional bass note is also used, e.g., "C/E". If the bass note is a regular part of the chord, it indicates the inversion, i.e., which note of the chord is lowest in pitch. If the bass note is not a regular part of the chord, it indicates an additional note that should be sounded with the chord, below it in pitch. The bass note can be any letter (A-G or a-g), with or without a trailing accidental sign (b or #). The case of the letter used for the bass note does not affect the pitch.

    Alternate chords can be indicated for printing purposes by enclosing them in parentheses inside the double-quotation marks after the regular chord, e.g., "G(Em)". But note that most ABC playback software will simply ignore such alternate chords. Music printing programs will just show the text as-is, of course. Whether transposing will effect alternate chords isn't predictable yet, and probably depends on just which program you are using.

    Examples? How about our Country Garden friend, this time with chords:

    X: 3
    T: Country Garden(s)
    Z: 1997 by John Chambers <jc@trillian.mit.edu> http://trillian.mit.edu/~jc/music/abc/
    P: A(A2B2C2B2)2
    M: C|
    L: 1/8
    K: C
    P: A
     | "G7"g2 g>f "C"e2 e2 | "D7"d2 d>c "G"B2 B>c | "G"d2 G2 "C"A2 c2 | "D7"B3A "G"G4 |]
    P: B
    [| "A7"g>a g>e "D"f2 d2 | "A7"g>a g>e "D"f4 | "A7"g2g>f e2a2 | f3e "D7"d2B>c |
    | "G7"d2 g>f "C"e2 e2 | "D7"d>e d>c "G"B2 B>c | "G"d2 G2 "C"A2 c2 | "D7"B3A "G"G4 |]
    P: C
    [| "C"G2c2 c2e2 | "D7"d>e d>c "G"B2 B>c | "G"d2 G2 "C"A2 c2 | "D7"B3A "G"G4 |]
    
    And here's what this looks like as a PNG file:
    Country Gardens
    The main thing to note about this is that some ABC programs will put the chords below the staff, and some programs may have an option to control this placement. Music publishers have been quite inconsistent about which position is "standard".
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    Multiple-note chords

    ABC's notation for multiple notes played simultaneously looks like:

    This is a written-out C chord, and will appear on a printed page with all the notes on one stem. Note lengths should go after each note in the chord: ABC can handle chords with different lengths for every note, but there are some qualifications about how well this notation works in practice:
  • Some playback programs are monophonic. They will typically treat the first note as the "melody" note, and only play that note.
  • Standard music notation can't handle different lengths very well, so you should use it sparingly. On the other hand, music-playing programs should be able to handle any lengths without difficulty.
  • Some programs will apply the length of the first note to all the others.
  • Putting a note in a chord twice, as in [ccA], will result in stems pointing both up and down with some programs (such as abc2ps); other programs will treat it as a single note.
  • Tieing or slurring notes in chords is not well defined, and probably shouldn't be used at present. However, ties or slurs applied to an entire chord should work without problems.

    Here's an example of the use of chords to write out a simple harmony. Note that the lower note is consistently written as the first of each "chord", so that monophonic players will treat it as the melody. (Of course, anyone familiar with this sort of Balkan tune will realize that either line can be considered the "melody" and the other the "harmony".)

    X: 1
    T: Sva Nok le, Nado
    O: Makedonija
    R: slow pravo
    M: 4/4
    L: 1/8
    K: F
    [| "C"[c3e3] [df] [ce][Bd] [Bd][Ac] | "F"[Ac][G2B2] [Ac] [GB][FA] [FA][FC] \
    | [FA][GB] [GB][Ac] "C7"[GB][Ac] [GB][FA] | "F"[FA][GB] [FA][CG] [FA][GB] [Ac][Bd] |
    | "C"[dB][ce] [ce][df] [ce][Bd] [Bd][Ac] | "C7"[Ac][B2G2] [Ac] "F"[GB][FA] [F2A2] \
    | [FA][GB] [GB][Ac] "C7"[GB][Ac] [GB][FA] | "F"[F8A8] |]
    [| "F"([F3A3] [GC]) [F2A2] ([FA][GB]) | ([A3c3] [GB]) ([GB][FA][F2A2]) \
    | ([FA][GB]) [A2c2] "C7"([GB][Ac]) ([GB][FA]) | "F"([F3A3] [CG] [FA][GB] [A2c2]) |
    | "F"[F2A2] ([FA][CG]) [F2A2] ([FA][GB]) | ([A3c3] [GB]) ([GB][FA] [F2A2]) \
    | ([FA][GB]) [A2c2] "C7"([GB][Ac]) ([GB][FA]) | "F"[F8A8] |]
    [| "C"[c4e4] ([ce][Bd]) ([Bd][Ac]) | "F"([A3c3] [GB]) ([GB][FA] [F2A2]) \
    | ([FA][GB]) [A2c2] "C7"([GB][Ac]) ([GB][FA]) | "F"([F3A3] [CG] [FA][GB] [A2c2]) |
    | "C"[c4e4] ([ce][Bd]) ([Bd][Ac]) | "C7"([Ac][B2G2]) [Ac] "F"([GB][FA]) [F2A2] \
    | ([FA][GB]) [A2c2] "C7"([GB][Ac]) ([GB][FA]) | "F"[F8A8] |]
    

    Sva Nok Le Nado

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    Copyright 2001, 2002 by John Chambers