I downloaded the new iTunes and by doing lost all my songs, is there any way to recover my music ?

Can someone please help to recover all my music, I had a different computer before and I didnt transfer my music to my new laptop. I had all my muisc in my itouch though. I downloaded the new itunes and lost all my music, i will like to know what can i do to recover it ?

I will apppreciate it if someone can help me so that i recover all my music