for free transcripts or comments visit us at qanda.org. they are also available as c-span podcast. coming up tonight, the commune can caters has christopher harrison. then a look at the return of the taliban to afghanistan. and then an interview with bruce hearsener later. >> cspan 2 provides public policy meetings and on the weekends booktv. c-span 2 created by the cable industry and brought to you as a public service by your local cable or satellite provider. watch us in hd, like us on facebook and follow us on twitter. >> host: mr. harrison, what is pandora and how does it work? >> guest: it is what you may known as a personalized radio service. our technology is what sets us apart. our music genome primary. it was founded by a musician himself. he was frustrated because it was difficult for him to communicate with drouirectors. a director would say i want music that sounds like x and the director would say this sounds like x and he would no, no, something that sounds like x. so his idea was you could breakdown music into its genes and map that up to 450 different characterist c