Don't know if this has been mentioned, but you can hear sets from many of the performers at the Seattle Folklife Festival.
Here's how to do it (I'm listening to Slip & me right now. No, not 'cause I'm vain-- I have to provide publisher info to the festival for the songs we did...)
1. From the Folklife homepage, click Listen on the menu at the top of the page. 2. On the left side of the page, select Festival 2009. 3. Each day of the Festival is listed on the top of the page. Select the day you would like to hear. 4. Click the Play button to listen to the full streaming show. A volume control is to the right.