It's called YouTube Music, and it puts YouTube's entire music catalog into an audio-friendly setup. It's all too easy to overlook, but any Google Play Music subscription comes with access to a separate app that lets you listen to a massive library of live and rare recordings. Sure, all your music-playing basics are plainly present when you open up the app - but like most Google products, Play Music has more to offer than what's on the surface. With all the talk about streaming music this week, I thought it'd be a fine time to dive deeper into Google's own Play Music service and seek out some of its not-so-obvious advanced features.