chords in front of a chart, or notes in front of notes. A line without one of them is an error.
Charts
| separates bars. Inside a bar, the tokens split the bar into equal slots.
Each slot must be a whole number of sixteenth notes, so a
4 over 4 bar takes 1, 2, 4, 8 or 16 slots. Rhythm comes from the slots: _ Am _ Am plays on the off-beats.
A chart written as the same bars more than once is an error, because a pattern repeats it: Am F|Am F and Am F|% are Am F. Inside a bar, C C strikes the chord twice.
A long chart continues on the next line when that line starts with |.
Chord symbols
A symbol is a root, a quality and an optional bass note:C, Am, F#m, Bb7, Cmaj7, G7sus4, Em7b5, Cadd9, C6/9, C/E. No quality means major.
A 6/9 chord is written as on a lead sheet, C6/9 or Cm6/9. Its / is part of the chord, so C6/9/E is C6/9 over E. C69, C6add9 and Cmaj6/9 are errors.
Roman numerals
A Roman numeral is written in lowercase, and the key’s mode makes its chord. A plain numeral is the triad the scale has on that degree, so it is major, minor or diminished as the scale makes it: in C majori is C, ii is Dm and vii is Bdim, and in C minor i is Cm, iii is Eb and ii is Ddim. A 7 after it is the scale’s seventh chord on that degree: i7 is Cmaj7, ii7 is Dm7 and v7 is G7 in C major. The same chart in another mode plays that mode’s own chords, which is how to hear what a mode does.
Degrees count on the key’s own scale, as degrees in notes do: in A minor iii is C and vii is G, and in A major they’re C# and G#. A b or # in front moves the root off the scale, to a major chord: bvii in C major is Bb. A numeral takes ' marks as a degree does: i' is the tonic chord an octave up and 'i an octave down, so a chart that climbs the scale ends higher than it began. To say a chord outright instead of taking the scale’s, write its quality after the numeral as you would after a chord’s root: vm, vM, vdim, vmaj7, v7alt, and vdom7 for a dominant seventh.
The first plays Dm Em F G Am Bdim C Dm, the second Dm Edim F Gm Am Bb C Dm, and the third D E F#m G#dim A Bm C#m D.
Counting from a chord
of counts a numeral from another chord’s root instead of from the key’s: v7 of v is the v7 built on the key’s v, a secondary dominant. The numeral counts on the major scale of that root, so in C, v7 of v is D7 and ii7 of iv is Gm7. After of goes any chord, a numeral of the key or a name of any type: v of Am is E, and v7 of Cmaj7 is D7. Only its root counts, so v of Am is the same as v of Am7. A bass note goes at the end: v7 of v/F#.
To count from a chord that is itself counted with of, put it in brackets, as with notes. v7 of (v of v) is the v7 of D, which is A7.
In C, this plays A7, D7, G7, C.
Voicing
Guitars play the fretboard shape for each chord where one is known.transpose moves the sound of any instrument’s chords and keeps their names, so a guitar’s shapes under set transpose 2 sound as with a capo at the 2nd fret. Other instruments stack the chord’s notes upward from its root, with the bass note an octave below. A numeral’s root counts up from the key’s root in the current octave, as a degree does, so a progression keeps its shape in every key: i vi iv v is C3 A3 F3 G3 in C and E3 C#4 A3 B3 in E. A chord symbol’s root is in the current octave, counted from C. A numeral of another one counts up from where that chord’s root sounds, so in A, v7 of v is B4, a 5th above V’s E4. A bass note after / goes in the octave below, counted up from the key’s root for a numeral and from C for a symbol.