Consumers who want to use the much-hyped Spotify streaming...

Consumers who want to use the much-hyped Spotify streaming music service on non-PC devices such as cellphones, tablets and AV receivers will need to subscribe to the top-level subscription package, according to audio companies we polled Thursday. Already Sonos and Logitech are pushing Spotify’s premium $9.99-a-month service for owners of their wireless multi-room audio systems, which also stream Pandora, Rhapsody and Sirius XM, among others. The free, ad-supported and $4.99 PC-only versions of Spotify aren’t available on external devices including multi-room music systems, multi-room players or cellphones. A premium account is required for the service to be used on “external (non-PC) devices like our receivers,” said a spokesman for Onkyo. Subscribers to the premium plan can have the app on an unlimited number of devices, a spokeswoman for Spotify told us, but they can only stream on one device at a time. Users can play offline playlists on up to three devices, however, she said. Additional features of the top-shelf plan include higher sound quality and “exclusive competitions and offers,” she said. Although the top-tier plan is capable of streaming at 320 kbps, not all songs are available at that data rate, she said. Onkyo began uploading firmware updates via zip files Thursday that owners of its 2011 networked receivers could download to PC and install through USB ports on receivers, it said. Sonos called the Europe-based streaming music service “one of the most anticipated music services” ever to come to this country. To have Spotify on Sonos, consumers need a Sonos player, a Sonos controller app for Android, iPhone or iPad and the Spotify premium account, Sonos said. Denon, which also sells Internet-ready AV receivers and was one of the first to support Apple’s AirPlay, didn’t respond by our deadline about whether its receivers would have access to Spotify. Spotify said its library is at 15 million tracks “and counting.” Spotify is offering U.S. users six months of unlimited free streaming, a spokeswoman for the on-demand music service told us. Its formal launch in the U.S. Thursday capped two years of false starts and frustrated negotiations with major labels. Spotify bragged Thursday that 15 percent of its users in Europe were paying subscribers, either to its Unlimited desktop-streaming plan or Premium mobile-phone plan; it passed 1 million subscribers this spring. The ad-supported free version in the U.S. is invitation-only at this point, the spokeswoman said: Those with an invitation can listen with no limits for six months, after which the free offering will cap listening to 10 hours a month and five plays per track. “We're going to see how things go over the next few weeks as to how many invites will be distributed and how long the free service will be invite-only,” she said, calling invitations a “hot commodity.” Users can sign up on the invite list at Spotify.com. Those who purchase a subscription can get immediate access. When the invitation-only phase ends, users can get 20 hours of free streaming a month for six months, at which time the free service will revert back to 10 hours and five track plays, the same limits as its European service. Spotify makes it easy for users to share tracks with friends and, in a feature already drawing raves from U.S. users on Twitter, lets users listen to songs offline. Spotify CEO Daniel Ek said on its blog that the U.S. service would launch with brand partners Coca-Cola, Sprite, Chevrolet, Motorola, Reebok, Sonos and News Corp.’s The Daily for iPad. Giles Cottle, Informa Telecoms & Media principal analyst, said Spotify could only succeed in the U.S. if it repeats its formula in Europe: “A clean, intuitive user interface, deep links with properties like Facebook and Last.fm (a Pandora deal is not out of the question) and high penetration across mobile handsets and other devices.” But Spotify has a steep hill to climb in the U.S., he said, with “limited brand awareness,” established on-demand competitors like Rhapsody and Napster, upstarts like Mog and Rdio and 100-million user Pandora. With no brand having broken a million paying users, Spotify will be considered a failure if it only manages to “poach a few users from its competitors,” Cottle said. And it may not draw the large user base it needs to placate major labels if it is “forced to cap its free offer too quickly,” he added.