How to transfer non-purchased songs from iphone to itunes?

I recently got a new computer and wish to transfer the songs i synced onto my iphone from my old computer onto my new one, the only problem is i didn't purchase these songs from the itunes store. Even when i plug my iphone into my computer and i view the iphones storage all it gives me is pictures and videos. Does anyone know how i can transfer these files onto my new computer?

I know but i'm just about to make a sandwich, ill get back to you later if i remember bro, think i'm going for tuna