Apple Music's rapid growth is pretty impressive, considering its rival Spotify took six years to surpass the 10 million threshold, the report said.

Apple Music made its debut in June 2015, launching in more than 100 countries. In October, Apple CEO Tim Cook said it had 6.5 million paid users, and an additional 8.5 million using the free trial.

In response, Spotify told us that it saw the fastest subscriber growth ever in the second half of 2015. It didn't disclose the exact number, but Business Insider's Jay Yarow estimates there were 25-30 million subscribers at the end of 2015.

Spotify, last valued at roughly $8 billion, is the clear leader in the music streaming app market. It hit 10 million subscribers in 2014, and said it had 20 million paid members as of June 2015.

Mark Mulligan, a respected music business analyst, recently forecast that Apple Music will get to 20 million subscribers by the end of 2016. That won't put it ahead of Spotify, but make it a clear number two in the music streaming business in just a little over a year.

But it's also wroth noting that Apple Music is baked into Apple’s entire software lineup, from iPhones to iPads to Mac computers, meaning it was immediately available to millions of people via millions of devices when it launched in late June. In fact, as Tech Insider's Dave Smith points out, it had more trial subscribers (11 million) than it has right now (10 million).