Cheat sheet:

Notation	Description
S(...)	Content played sequentially. Content may be notes or instructions that apply to all succeeding notes.
P(...)	Content like S but played in parallel. S and P may be arbitrarily nested.
c0, cs0, df0, ..., cf7, c7	Notes with absolute pitch.
c, cs, d, ... bf, b	Notes with pitches relative to most recent pitch (LilyPond style).
+x, -x	Relative pitches one octave higher or lower (LilyPond x' or x,)
r	Rest.
x/1, x/2, x/4, ...	Whole, half, quarter, ... note duration for note or rest x.
x/(1,2), x/(1,2,4), x/(2,4), ...	Dotted whole note, double dotted whole note, dotted half note, ... Duration as fraction of a whole note is sum of reciprocals.
v0, v1, ..., v100	Absolute volume instruction for succeeding notes, on a logarithmic scale.
x/v0, x/v1, ..., x/v100	Absolute volume for x and succeeding notes.
x>v	Volume adjustment v for note x. May be positive or negative. Added to absolute volume.
x>(v,w)	Volume adjustment varying from v at start to w and end of note x.
x>[v0,v1,...]	Volume adjustment spanning multiple notes starting with x. v0 is applied to x, v1 to next note, and so on.
x>[(dur0,v0),(dur1,v1),...]	Volume adjustment possibly spanning multiple notes starting with x. Volume adjustment v0 for dur0, then v1 for dur1, ... Dur is 1, 1/2, 1/4, ... for whole, half, quarter, ... note. x may be a note or an instruction such as bar check I.
x>[(dur0,v0,w0),...]	Volume adjustment varying from v0 to w0 over period dur0.
x@p	Pitch adjustment p for note x in units of semitones. May be positive or negative. Added to normal pitch for x.
x@(p,q)	Pitch adjustment varying from p at start to q and end of note x.
x>[p0,p1,...]	Pitch adjustment spanning multiple notes starting with x. p0 is applied to x, p1 to next note, and so on.
x@[(dur0,p0),(dur1,p1),...]	Pitch adjustment possibly spanning multiple notes starting with x. Pitch adjustment p0 for dur0, then p1 for dur1, ...
x@[(dur0,p0,q0),...]	Pitch adjustment varying from p0 to q0 over period dur0, ...
x*n	Repeat x n times, where x is S(), P(), or a note.
I	Bar check marker instruction. (LilyPond |)
t/dur	Tied note. Extends previous note by dur. Useful for notes that cross bar boundaries.
h/dur	Hold. Extends previous note by dur but does not count against beat.
p/dur	Pause. Like a rest but does not count against beat.
guitar, clarinet, saxophone	Instrument instruction. Applies to all succeeding notes.
time(m,n)	Time signature m/n.
tempo(m,n)	Tempo marking: 1/m note is n beats per minute.
transpose(n)	Transpose all succeeding notes by n semitones.