If you're one of the guys running their PSP on Team M33's Custom firmware v3.71, we've got some good news. amirulrudy12 over at the QJ.NET forums reports that developer Tabula has just created a music Prx for the said CFW.

It's also been reported to run successfully on the PSP Slim.  Before you download Tabula's plugin, however, be warned that it's still a beta build, and thus it still has plenty of bugs. Quoting the observations made by recent users:

• This keeps freezing my PSP after switching songs a few times... Also, every time I try and access Music from actual memory stick option, and try and play a song, instantly freezes up.
• it crash with VSH menu when pressing NOTE|SELECT. And it crash with Cwcheat..after u enter the game..no way out..
• It only works while i am playing. Is not working in the internet or xmb.
• psp crashes after 5 musics....