Google added another level of complexity to its YouTube brand / music strategy on Thursday with the launch of YouTube Music for Android and iOS.

YouTube Music is the brainchild of YouTube Music Key, the subscription-based music service that launched as a limited beta last November. In my coverage at the time, I described Music Key as the long-rumored subscription-based music service that we'd heard so much about leading up to that point. As it turns out, that wasn't the case at all as Music Key never made its way out of beta. Instead, the service served as a proving ground and a source of feedback / inspiration for what would ultimately become the platform's main attraction, YouTube Music.

The new app taps into the vast music collection of the world's largest video sharing site. It's a free, ad-supported service designed to make discovering music on YouTube easier than ever through personalized recommendations that include curated playlists based on your YouTube history, covers, dance mixes and more.

YouTube's goal is to create an endless loop of playback to keep users engaged as long as possible. That's done through the aforementioned recommendations and a "radio station" of sorts that can have as little or as much variety as you want.

YouTube Music is tied into YouTube Red, the company's recently-announced subscription service that offers an ad-free experience with offline viewing for $9.99 per month. A subscription to Red will unlock the full potential of YouTube Music, eliminating all ads and introducing some other premium perks like an audio-only mode and offline playback.

Videos that you "like" are added to the offline playlist, known as an offline mixtape. In the settings, you can adjust the number of mixtape tracks to take offline up to a maximum of 50 tracks which is around 200 minutes of tunes requiring 2.62GB of free space.

As you may recall, YouTube Red also grants full access to Google Play Music, the search giant's primary streaming music service.

There's certainly a lot of overlap here with Google Play Music and YouTube Music. Perhaps the best way to differentiate the two is to think of the former as a traditional streaming music service like Spotify that you'd use to seek out a very specific song. YouTube Music is best for music discovery or casual background listening. It may sound silly but even after just a short time with YouTube Music, it's clear that it really does offer a unique experience. With it, you're basically giving up control for convenience.

YouTube Music is available as of writing for Android and iOS. It comes with a 14-day free trial although if you're really interested, take the YouTube Red approach as that service offers a free trial for a full month.