Custom Music in MLB12: The Show

I'm not a particularly huge sports games fan.  I buy one of each franchise I'm interested in per generation.  I happen to be dating someone who's particularly interested in baseball, and so I've put quite a bit of work into figuring out how to make the music a lot more authentic, including batter walk-on music, 7th inning stretch music, and stadium themes.
 The general idea is this: you download music, place it on a flash drive, and take the following steps:

• Copy the music into your PS3's MUSIC section.
• Load MLB12 (or MLB11, and this will also likely work on MLB13)
• Go to Sounds of the Show -> Playlist Editor -> In Game Music Cues

For stadium music, here's a Google document that gives you a good idea of what music to play when.

For walk-on music, go to Manage Roster, select your player, edit him, and choose your file, and assign it.

Thanks to the Sounds of the Show forums on Operation Sports and the official NL and AL forums.