just a simple question:
what classical songs can be used as influence to metal or shredding, maybe pagnini?

if you can tell me the name of the sonata or something please.
Maybe Paganini's "Caprice no. 24". You should try to play the whole piece.
Paganini's "Moto Perpetuo".
Frederic Chopin's "Fantasie Impromptu". That one covers a lot of different techniques.
Some Antonio Vivaldi pieces are good exercises too.

That's all I can think of right now.