All the music can be streamed as http://server/rsp/stream/
, if you know the song id (which is in the database).
Is seems this only works with MP3s. I tried a couple of FLACs and my player complained about it being an unsupported format (foobar can play FLAC)
It’s not broken on the daap server side. You can try playing with “never_transcode” and see if you can force it to flac or wav, and see if foobar has better luck with it.