Come on, if you look at the Highscore, you can see that it is not too hard. It's difficult, but with some research and stylistic knowledge you can be successful even without know the pieces. If you got the piece, you can google the opus number, that's not the problem.
If you think the first one is Mozart, you can easily find the correct piece. ;) You got the key and time signature, articulation (so that you can think of the instrument it's written for), ...
Good luck! :)
And don't give up too early! You can use this thread to give or ask for hints.