I would recommend some of the tracks by the group All india radio http://www.myspace.com/allindiaradio http://www.myspace.com/allindiaradio . I use it effective

I would recommend some of the tracks by the group All india radio http://www.myspace.com/allindiaradio http://www.myspace.com/allindiaradio . I use it effectively to differentiate the signal from the noise ! :) Anything without lyrics works for me