I just got a myTouch, running Google's Android OS (1.6 cupcake). I'm gonna post here 'cause I haven't gotten any responses from the phone-related sites I posted my question on.
The OS isn't reading any of the tags on the m4a files. It should, and if I use mp3tag to strip the tags from the files, then rewrite the fields manually, the phone reads the tags fine. :/
Most of my music library is made up of CDs I ripped using iTunes. After ripping I load 'em into foobar2k, apply replaygain, then use an mp3tag script (that I found out about here a while back) to convert the album gain values to iTunes Soundcheck.
I've scoured Google for answers but noone else seems to be having this problem so I'm assuming that something in my volume-leveling process is doing something to the tags that makes them unrecognizable to the phone's OS.
I'm hoping someone here with more technical info on mp4 tags than me can help figure out what's going on here. And if not, maybe we can brainstorm and figure out a way to batch edit the tags so they read correctly on the phone. I've tried deleting the artist field in an album, saving the tags, then adding it back to all the tracks simultaneously using mp3tag, but that didn't work.
Please help.
edit: also tried embedding album art in an album to see if that changed the tags properties, and tried the Optimize MP4 option on a couple of albums - no luck.
edit: correction, I think Android 1.6 is called donut, not cupcake. 1.6 is def the one I have