I know workarounds suck for something like this, but there is another one available if you don't want to stop using the TW music player, and you don't want to delete or relocate your music.
Basically, you copy all artist information to Composer in the ID3 tag, and hide the artist tab in the TW music player. All functionality will be there.
I used mp3tag, and it worked really well.
If anyone is interested...
1. Load up your music in mp3tag
2. Select all your music in the app.
3. Push Alt-5.
4. On top right, click on "New".
5. Name it anything you want.
6. Click on "New" again.
7. On the drop-down, click on "Format Value".
8. In Field, select "COMPOSER".
9. Click on the right arrow next to Format String, and select "Artist".
10. Click OK... OK.... Make sure that only your new action is checked, and click OK again.
11. Click on Save.
This doesn't rename your files or change functionality or usability at all.
Now your music is formatted so that when you show the Composer tab on your Vibrant, it will show you all artists.