Amazon on Thursday took the wraps off Prime Music, its music-streaming service available to Prime members, touting a library of more than 1 million songs — without any ads.

Currently, however, Amazon does not have a deal with Universal Music Group for Prime Music. That’s a major omission, given UMG’s 38% share of the market with such artists as Katy Perry, Taylor Swift, Lady Gaga, Kanye and Jay-Z.

Prime Music’s million-plus songs include tracks from Daft Punk, Justin Timberlake, P!nk, Bruno Mars, Blake Shelton, The Lumineers, Bruce Springsteen and Madonna. Amazon has agreements with labels including Sony Music Entertainment and Warner Music Group. Under the terms of deals with music companies, songs will be available on Prime Music no sooner than six months after they debut.

Steve Boom, Amazon’s VP of digital music, said “discussions are ongoing” with UMG about a licensing deal. He declined to comment further.

With the launch of the service, the ecommerce company will challenge similar music services from Spotify, Pandora and Apple. Amazon is bundling the music service with the $99-per-year Prime service, which provide free two-day shipping and unlimited video-streaming through Prime Instant Video.

“Today we’re introducing Prime Music — more than a million songs from some of music’s best artists, plus hundreds of expert-programmed Prime Playlists, all at no additional cost,” Amazon founder and CEO Jeff Bezos said in announcing the launch. “Prime Music is the latest great addition for Prime members and we think they’re going to love it.”

Amazon noted other benefits of Prime Music compared with free alternatives. The service does not have any restrictions so users can skip as many songs as they want, or repeat their favorite song over and over again.

In addition, Prime Music lets users download music to a phone or tablet to listen offline. The service is available via apps for Apple iOS and Android devices, web browsers, Amazon’s Kindle Fire HD/HDX tablets, and apps for Windows PCs and Macs. Later in 2014, Amazon expects Prime Music to be available on the Fire TV set-top and the Sonos wireless speaker system.

As for whether Prime Music will erode Amazon’s digital music or CD sales, Boom suggested it could potentially increase sales. “People have different reasons for buying music,” he said. “People like to know they have permanent ownership.”

The company has scheduled an event for June 18, where it’s expected to unveil a smartphone that would challenge Apple’s iPhone and other Android devices.