[colomon]

ABC is very well optimized for single voice traditional instrumental music. In that domain (and with a bit of experience at it), it's very easy to write and read ABC:

  T:The Three Smokestacks
  M:4/4
  L:1/8
  C:Solomon Foster
  R:Reel
  K:G
  EF|G2BG FGAF|GBdg ecAF|G2BG FGAF|GEFD EDEF|
  G2BG FGAF|GBdg ecAF|G2BG FGAF|GEFD EDEF||
  GBdg e2ef|gefd edBA|GBdg e2ef|gefd e2dB|
  GBdg e2ef|gefd edBA|Beed efgf|ecAF GFEF|

The header L: field defines the default length of a note. In the body of the tune, uppercase letters A-G are notes in the octave that starts with middle C, lowercase letters a-g are notes in the octave above that. A number following a note name is a multiplier for the note length. Bar lines are pipes.

The drawback to ABC is as you wander away from that original use case, it gets harder and harder to use. Here's snippet of an arrangement of Sleigh Ride I was working on a few years ago:

  z +mf+ (+accent+e .^d/) z/ z|(+accent+e .d/) z/ z +p+ .^F/.=G/||[K:G bass octave=-1] +crescendo(+ .A .A .A .A|.A .A .A .A|+f+ +crescendo)+ +accent+ d zz +sfz+ G|

Studying it again, I can mostly figure out what it is trying to do -- z is a rest, things surrounded in +s are extra commands, so +p+ and +f+ are dynamics, +accent+ puts an accent over the next note, etc. It's still pretty easy to understand, but I'd have a hell of a time playing the music from that notation. And I coded up that ABC, if someone else had done it there's a decent chance I'd have to stop and look up some of their notation in the ABC standard.