Q: why do i have music in my iphone that is not mine?

Hi lissette17,

Thanks for visiting Apple Support Communities.

You can use these steps to delete songs from your iPhone:

Before you delete, find out if you'll be able to download the song you deleted again (it depends on where you live). To delete a song:

1. Tap the Music app.
2. Tap the Songs category.
3. Swipe left to right over the song you want to delete.
4. Tap Delete.

From:

How to delete content you've downloaded from the iTunes Store, App Store, iBooks Store, or Mac App Store

http://support.apple.com/kb/HT5772

All the best,

Jeremy