Abc (music notation)
Abc is a special-purpose programming language for creating musical notation, where melodies are represented in the ASCII character set by the letter which corresponds to each musical note. Because of the correspondence of letters and notes, abc notation tends to be learnable by musicians who are not necessarily computer programmers. Since the introduction of the first freeware compiler in 1993, the abc language has achieved widespread use for folk and traditional tunes which are typically single-voice melodies on a single staff. With multiple freeware compilers now available, the abc language continues to grow in popularity because it provides a cost-free alternative for creating musical scores, and because it provides a standard way for people to share tunes and scores on the world wide web. Although not held by any tranditional standards body, abc can be considered to be a de facto standard due to widespread, voluntary compliance by software authors to certain written specifications.
Example
Here is the source code for a reel called Dickey's Discovery:
X:1 T:Dickey's Discovery C:Unknown, transmitted thru Lotus Dickey to Pete Sutherland M:4/4 N: Q:1/2=120 L:1/8 R:reel N:taught to Pat Palmer by Garry Moore July 2007 N: R&O XXVIII K:D dB|:"D"A2FG FEDE | FA2B A2dB | "D"A2FG FEDF | "A"EDEF E2 dB| "D"A2FG FEDE | F2A2 f2fe | "G"d2Bc "A"BAFG |1 "D"A2 D2 D2 dB:|2"D"A2 D2 D2 (3ABc| |:"D"d2d2 "A"egfe | "G"dedB "A"ABcA | "D"dcde "Bm"fefg | "A"a2e2 egfe | "D"d2d2 "A"egfe | "D"fgaf "A"egfe | "G"d2Bc "A"BAFG |1 "D"A2 D2 D2 (3ABc:|2"D"A2 D2 D2 dB|] w: v4
and here is how the above code is rendered as a .pdf document: