Persian Music web radio
What I've heard so far sounds first rate, unadulerated by cross-overs. It mixes up meditative pieces for small ensembles with one or two solo instruments (tar, setar, violin, etc,), vocals of various sorts, and larger, more orchestral groups. Radio Darhish doesn't give any information on the tracks, but you can find info on many of the artists here:
Persian music, much of which is steeped in Sufi mysticism, has a controlled fervor that I find very moving.