The simplest case, a triplet of notes, is easy:
(3 FGAThis means the 3 notes FGA in the time of two notes. Note that there's no ) at the end, and spaces are irrelevant. For this simple case, the 3 notes should have the same length.
ABC can represent general n-tuplets using the syntax:
(p:q:r ...This means "put p notes into the time of q for the next r notes." There are a few special cases. If r is missing, it defaults to p. For example: If q is missing, it defaults to [undocumented at present].
Note that music formatting programs actually ignore the q value, though it is used by music playing programs to determine how long the p notes should take. A formatting program should produce the usual "bracket" marking the next r notes, and put the number p above or inside the bracket.
Special cases:
(3::2 = (3:2:2 (3 = (3:2:3
Copyright 2001, 2002 by John Chambers