ABC Music Notation: Tunes

ABC is written in chunks; each chunk is called a "tune". In its simplest form, a tune consists of two parts:

header lines: Information about the tune as a whole.
music lines: ABC notation for the notes and chords, and possibly lyrics.

A blank line indicates the end of the tune. In the previous example, the headers are:

	X: 1
	T: Paddy O'Rafferty
	C: Trad.
	M: 6/8
	L: 1/8
	K: D

Let's look at these one at a time.

X: 1

The first line must give an index number to the tune. This is like the track number on an album. It is used by assorted ABC software to select tunes from a file with more than one. Some people leave out the X: line in single-tune files, but this tends to confuse a lot of ABC software. So it's a good idea to always include one, even if there is only one tune in the file.

T: Paddy O'Rafferty

The second line gives a title, and may be repeated for tunes with several titles. Different programs may have limits to the number of accepted titles, but everything seems to accept at least four.

C: Trad.

This gives a composer. If the composer isn't known, this line may be omitted. If the tune is definitely known to be traditional, it might a good idea to indicate this, so people don't think you forgot to give proper attribution.

M: 6/8

This is the meter. It defaults to 4/4. The usual fractional notation may be used. You can also use C for common (4/4) time, and C| for cut (2/2) time. (That's a vertical bar, not the letter l or the digit 1.) Many programs also accept M:none to indicate a free rhythm with no time signature.

L: 1/8

This is the unit note length. Notes may be followed by a length (a fraction), which is multiplied by this to get the actual note length. The default is a bit complicated: For meters that are numerically 3/4 or longer, the default note length is 1/8. For meters that are numerically less than 3/4, the default note length is 1/16. It's probably best to always include the L: line and not depend on defaults.

K: D

This gives the key, and must be the last line of the header. The classical modes are recognized, and may be abbreviated to their first three letters. Minor can be indicated by just "m". Some examples:

ABC	key	signature
K:D	D major	2 sharps
K:Dm	D minor	1 flat
K:Dmin	D minor	1 flat
K:Dminor	D minor	1 flat
K:DDor	D Dorian	No sharps or flats
K:DDorian	D Dorian	No sharps or flats
K:DMix	D Mixolydian	1 sharp
K:DPhr	D Phrygian	2 flats

This isn't nearly the whole story for headers. There are a large number of other header lines defined. And most of the lines can also be used inside the music section of a tune to change the information. See the Headers section for a full description. But the above header lines are all you really need to type in tunes, so let's barge ahead with the notes.

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