What are some good free music apps for iPhones?

I currently have McTube Pro and it's decent, it just takes up way too much storage space. Basically, on McTube, you're supposed to be able to download YouTube videos, including songs on YouTube. The videos you download are still accessed through the app, though. My iPhone is full and I need to clear up some storage space fast! I know I can delete pictures and stuff, I've deleted practically all my unnecessary apps and even some of the ones I kind of need. My McTube Pro app is taking up 5GB because I have like 600 songs. I know about like Pandora and iHeartRadio and stuff but I want one where I can choose specific songs, possibly one that works without Wi-Fi or good service because I have Sprint which had spotty service. I don't mind paying a few bucks for the app, I just don't want to pay a dollar per song like on iTunes, any app suggestions?

Personally iTunes Radio is my favorite

I use iTube and it's my favorite music app! But I think it takes up a lot of room. Try MP3 apps. I use MP3 Music Free, and it has like a lavender-ish icon. Or, you can use the Youtube-MP3 converter from your computer and it'll go into itunes and be put into your music library.