One of the key elements of an ABC tune is the “header,” which contains information about the piece such as its title, composer, meter, key signature, and other important details. The header is typically the first section of an ABC tune. In this article, we will explore the tune header in ABC notation. Here’s a simple header:
X: 1
T: The Wise Maid
R: reel
M: 4/4
L: 1/8
K: Dmaj
The first field, X: is the reference number, and it marks the beginning of the tune.
X: 1
Each tune must start with a reference number field.
T: and R: indicate the title and rhythm:
T: The Wise Maid
R: reel
M: indicate the meter, as it’d be displayed in a score.
L: is the base length: every note in the tune will be either this length or a multiple of it.
More of this later.
M: 4/4
L: 1/8
K: is the key, often indicating also the tune mode
K: Dmaj
L: indicates the default length of notes.
This value will be employed to calculate the duration of all notes.
In the example below, the C note had a duration of 1/4:
L: 1/8
C2
For more details about notes duration, see the notes post.
The L: field sometimes is omitted; when this happens, a default duration of 1/8 is assumed.
These are most important information fields; to learn more about all the other fields see the official ABC Notation Website.