[sciurius]

Something that would be nice to agree upon: sub-separators. For example, a song can have multiple composers, keys, signatures, collections, etc..
There's an (informal) advice to use semicolon to separate the fields (because of commas in page ranges), how about an (informal) advice to use a vertical bar to separate subfields? Bonus points for a space-surrounded bar .

Code:

title;pages;keys;composers;year;signatures;collections;source types;genres
Sunday;9;Bb;Chester Conn|Benny Kreuger|Jule Styne;1926;4/4;The Firehouse Jazz Band Fake Book;Sheet Music;Jazz
Bill Bailey, Won't You Please;10-11;F;Hughie Cannon;1902;4/4;The Firehouse Jazz Band Fake Book;Sheet Music;Jazz