New York - AmieStreet.com, an online music retailer that offers variable song pricing, announced on Tuesday that top independent labels Beggars Group, Matador Records and Polyvinyl Recording have signed on to use its service. The Amazon.com-backed company offers "fan-driven" pricing, where songs are initially free and then rise in price based on popularity, up to 98 cents. With the new deals, AmieStreet.com will now offer songs from artists including Cat Power, Sigur Ros, Pavement, Yo La Tengo and Interpol.