Amazon, the internet's largest retailer, is making an aggressive move into the booming and intensely competitive business of streaming music.

The company will expand its Prime membership offerings by adding a stockpile of old and newish music for subscribers to stream on demand. The Prime music service, which is scheduled to launch this June or July, will not include recent releases but instead restrict its catalog to songs and albums that are 6 months old and older, five music industry sources familiar with the company's plans confirmed to BuzzFeed.

Similar to Prime Instant Video, the on-demand video option available to Prime members, the Prime music service (the official name of which is still unknown) won't aspire to the full universe of existing content, instead offering a potluck of select songs and albums it has licensed from labels at a discount. That distinguishes it from the prevailing business model of stand-alone streaming competitors like Spotify, Rdio, and Beats Music, all of which have tried to lure customers by promising all of the world's music with a few precious exceptions.

Of course, Amazon has already hooked over 20 million reported Prime members without offering any music at all. For Amazon, music is yet another cherry on top of a cake that already includes movies and TV shows via Instant Video, an e-books lending library for its popular Kindle reader, and free two-day shipping — the service's signature feature since debuting nine years ago. It sweetens the deal not long after Amazon miffed some members in March by raising the price of Prime to $99 per year from $79.