Here is another annotated diagram showing a process. These are the sound cue sheets (not in their original color, alas) for the mix of Apocalypse Now, drawn by Walter Murch; from the excellent new book by Michael Ondaatje, The Conversations: Walter Murch and the Art of Editing Film (New York 2002).
I prefer the funky, workaday, documentary style here rather than the geometric purity of the example below.
This is an interesting design. Here are some improvements. Eliminate the dreaded legend by putting the labels for the instruments at the beginning and end of the time lines:
The annotative style is good; place the words closer to the time line. The central axis type is inefficient; flush right/rag left instead will allow more detailed annotation. Put the whole thing on a very light grid background to encourage writing notes by hand on a printed version. Add a time-scale at the bottom. Add details about the source, date, place. Perhaps the words of the piece should flow along in parallel beneath the graph of the musical sounds.
-- Edward Tufte