Musicians are furious that new tech has gutted their income. Record labels are wary, yet eager to cut deals with ascendant platforms. Fans are delighted to access songs for a pittance, even as they’re screwing over beloved artists. The fears about today’s streaming economy echo the existential panic when Napster debuted in 1999. The peer-to-peer service — where fans swapped catalogs of MP3 song files — walloped the record business. It helped demolish billions in label revenue, forcing a sclerotic industry to re-assess its entire model. It scrambled loyalties among fans, artists, tech companies…