to vjc：Now, there is no any ”PSP Music Format” yet.
We know, PSP music format has like AT3, ADPCM, and other format. The ADPCM format music, you can rip it by PSF2 stream format. and, AT3 files, you can use some tools to convert it.
But, the sequence music, there is no any format now. By the way, I think it will until the PSP can be full emulated in PC.