I've mentioned Spotify a couple of times - it's a great music-searching and -playing tool - completely free if you use it from a PC or laptop (but you only get a free trial on mobile devices). As my laptop is upstairs where I work, it's perfect for me. Yes, it would be nice to listen to it on my iPad, but I really have no need for it. We have music in most rooms - more than I need.
Yes, there is advertising on the free version, but I don't mind. It's ideal if you want to listen to a piece of music, but you're not sure if you want to actually buy it. You can listen to it as often as you want, you can place it in a personal playlist, and then you can go looking for more music. Knowing myself, I'll still be listening to La Clemenza di Tito in the new year! When I was a teenager, I would play my Neil Diamond LPs over and over!