Transfer music

My itouch is filled with musics from my friend's laptop. What would happen to the musics if I were to sync it to my own laptop? I don't own any of the songs. Is there any ways that I can transfer these musics from my itouch to itunes on my own laptop?

Because everytime I'm about to click 'sync', this message pops up "Music, films, TV programmes, books and tones synced to device from outher iTunes libraries will be removed and items will be synced from this iTunes library". I didn't proceed with it because I was afraid of losing all the songs in my iTouch,

Please help because I would like to update my playlist!