Voices of Music, the little band of hard-core early music players, is a presence on the web through their music videos on their YouTube channel and Vimeo. You can hear them live this weekend in a concert of 17th-century fantasias by a group of composers you may never have heard of.
That's actually a lure: You can go to this concert and be surprised (and delighted). Most of the players come from the Philharmonia Baroque Orchestra and that in itself is enough of a recommendation.