Here is a great article about Kirtan and Hinduism. The number of people who are participating in kirtans in the west is rising (due to the overall increasing popularity of yoga) and many of the people participating do not follow any of the paths normally associate with kirtan (Hinduism, ISKCON, Sikhism, etc). It's interesting to look at why peopel want to chant when it isn't part of their religious traditions. I think it speaks volumes to the power of taking part in a community event in which one doens' thave to do anything but be there making a joyful noise.

Article from Filmy Friday: Kirtan and Hinduism specialists exchange views on ecstatic chanting

Kirtan (chanting) as a vehicle of divine bliss was discussed when Dave Stringer, one of the most gifted singer of kirtan genre, and Rajan Zed, acclaimed Hindu statesman, met at Truckee in California.