|: CDE FGA | Bcd efg :|This is a two-bar repeated phrase. Sometimes you see multiple colons:
|:: CDE FGA | Bcd efg ::|This is not part of the official ABC notation standard yet, though it isn't forbidden. Some ABC programs understand it, but many don't.
There is also an abbreviation: :: means the same as :|:, a bar line with repeat indicators on both sides. How it is drawn may be different for different programs.
Repeated phrases frequently have different endings on the repeats. There is a standard way of handling this in ABC:
|: CDE FGA |1 Bcd efg :|2 Bcd eBc :|The use of a number like this immediately after a bar line indicates an alternative ending in the obvious manner. However, this notation currently has a serious limitation. Many ABC programs only recognize |1 and |2, but won't accept any other numbers. This is a topic that has led to some discussion, and it may be fixed eventually. The final decision isn't in, but we can expect something like:
|: CDE FGA |1,3 Bcd efg :|2 Bcd eBc :|4 Bcd c3 :|
Another scheme used by some musicians (especially dance musicians) is to label all the parts of the tune, and then give a repeat pattern at the top of the tune, usually at the upper left. ABC can do this, and most ABC software understands it. For example:
X: 1 T: Country Garden(s) P: A(A2B2C2B2)2 M: C| L: 1/8 K: C P: A [| g2 g>f e2 e2 | d2 d>c B2 B>c | d2 G2 A2 c2 | B3A G4 |] P: B [| g>a g>e f2 d2 | g>a g>e f4 | g2 g>f e2 a2 | f3e d2 B>c | | d2 g>f e2 e2 | d>e d>c B2 B>c | d2 G2 A2 c2 | B3A G4 |] P: C [| G2 c2 c2 e2 | d>e d>c B2 B>c | d2 G2 A2 c2 | B3A G4 |]Here's how this comes out as a PNG file:
Note that the P: lines are being used in two different ways here. Within the header portion of a tune, P: gives the order of the parts. Within the music portion of a tune, P: is used to label each part. This notation is often used for Morris-dance arrangements of tunes, and for other kinds of dancing that require such complex arrangements.
There is an alternative way of labeling the parts that some software (such as abc2ps) accepts. You can put the label in double quotes before a bar line. This lets you put the label anywhere, not just at the start of a line. The above tune uses four staffs, and using P: lines doesn't let us decrease this much. But we can rewrite the tune in the following way, to reduce it to two staffs:
X: 4 T: Country Garden(s) P: A(A2B2C2B2)2 M: C| L: 1/8 K: C "A" | g2 g>f e2 e2 | d2 d>c B2 B>c | d2 G2 A2 c2 | B3A G4 \ "B"[| g>a g>e f2 d2 | g>a g>e f4 | g2 g>f e2 a2 | f3e d2 B>c | | d2 g>f e2 e2 | d>e d>c B2 B>c | d2 G2 A2 c2 | B3A G4 \ "C"[| G2 c2 c2 e2 | d>e d>c B2 B>c | d2 G2 A2 c2 | B3A G4 |]This has the advantage of bringing out visually the similarity between the A part and the second half of the B part. Here's what it looks like as a PNG file:
Copyright 2001, 2002, 2010, 2015 by John Chambers