I've recently discovered that at the web site of Trinity Church — a very old church in lower Manhattan, across the street from the World Trade Center site — has a page of full-length videos of events at the church. There are speeches, lectures, discussions, sermons... and there's music. There frequently are concerts at the church, and they're recorded and posted there. Mostly it's classical — choral and chamber music — but there's the occasional other sort, like Jerry O'Sullivan, Donald Clancy, and Bernadette Fee playing Irish music, or the group called Alhambra playing Sephardic music. You can hear (and see) string quartets, brass quintets, chamber orchestras, and a cappella singing. There's Shostakovich and Schumann; there's Mozart, Bach, and Haydn; there's Handel's Messiah.
The recordings are available in three qualities of video, and as audio-only, so it can accomodate whatever Internet-connection speed you might have. I've enjoyed them using the "high" quality video on my cable connection. Unfortunately, they're only available as Windows Media streams; it would be great if they had the audio available as downloadable mp3 (as "podcasts").
Check them out!