Can you use an old iPhone just as an iPod?

Awhile ago i lost my ipod touch and just haven't wanted to pay another 200 bucks for a brand new one. My friend offered me his old iphone (3gs i think). I already have my own phone but it isn't a smart phone so it can't hold music. Is it possible that i can take his old iphone and connect it to my itunes and use it just as an ipod only for music?

Yes you can, you can use any iPhone just for music

Yes, the music and data won't be affected