PsiLoc's Multi Media Player has been ported to the 7650. It is currently in beta. It plays MIDI, WAV, RA, AU, SND formats and MP3 will be added soon via a plugin. PLaylists in m3u formats are also supported.
Whether this is practical or not on the limited memory 7650 is open to debate, but this program will be compatiable with future Series 60 phones that may have more memory.
More @ http://www.psiloc.com/nokia/eng/mmplayer7650/index.html