How to retrieve deleted songs?

I accidentally deleted all my songs in my finders and now i can't locate my music in my iTunes. Can i somehow retrieve the music by syncing my iPhone to my mac? I really don't want to download the songs again cause i have a lot of songs.

I don't know much about apple but i do know that if the file itself is on your iPhone than you should be able to recover them from it thats what i do if i accidentally delete a song i take it off of my mp3 player and there you go your song is back hope this helps.