The documents, officially filed by Beats Electronics LLC, which Apple purchased for $3 billion in 2014, and first noticed by Consomac, are for Beats 2, Beats 3, Beats 4, and Beats 5. As Appleinsider notes, the company has filed applications for both the logos and the names of these presumable stations.

Apple (AAPL) debuted Beats 1 in June, along with the launch of its long-awaited (and sorely needed) music streaming service, Apple Music, which mainly competes with Spotify and Deezer (Rdio recently shut down following its acquisition from online radio company Pandora). Beats 1 is a music radio station that can be accessed through Apple Music and iTunes, with a large amount of human curation—also known as “disc jockeying” in the old days.

Apple snagged BBC Radio’s Zane Lowe, as well as Julie Adenuga and Ebro Darden to give it credibility from the get-go. This is also an interesting contrast to well-known Internet music radio company Pandora—and new owner of former Apple Music competitor Rdio—which uses computer algorithms to select the songs it plays for each listener based on the songs and artists they select.

But it’s also not clear how much Beats 1 has contributed to Apple Music’s success, which as of October, had 15 million users, including 6.5 million paying ones, according to comments from Apple CEO Tim Cook at the time.

There’s, of course, no clue as to what exactly Apple plans to do with those additional stations. They could focus on specific music genres or verticals, like live performances. As the Verge pointed out in August, when it first reported that Apple was plotting more stations, the tech giant could also plant them in different parts of the world. This could mean content in other languages, or simply a way to cover more time zones.

The radio stations are also the last remaining digital music products with the Beats brand (not counting the headphones and speakers business) after Apple killed off Beats Music, Apple Music’s predecessor and foundation.