Trying to listen to music because i don't want to pay for music with iTunes and this is the best way i could think of. Just needed to know if it used up my data when i don't have wifi?
No, it doesn’t.
I gather that you’re recording songs from whatever source with the voice memo app and want to listen to them without using your data plan? Then yes, that’s a way of achieving that.
But if you own songs, you can easily transfer to your iPhone with iTunes from a computer.