Ipod won't unlock

Hello, i have about 400 songs on my ipod and i put it on lock and when i unplugged it and tried to unlock it it wouldn't unlock. And now on itunes it is saying that i have to restore my ipod but that will delete all of my songs and videos it said. Is there any othere way that you could help me unlock it so i can listen to my songs with out deleting them.
Thank you!