Secret service catches a violin player waiting for a bus. They arrest him, take him to an undisclosed location, build a case like this:
"The suspect works for a secret organization named Orchestra. He carries a suspicious looking communication device, files written in secret script under codename "notes", supposedly written by one Mozart (note: find this guy and all his contacts), handed to him by the chief of his organization's local branch (codename: symphony orchestra). Chief goes under codename conductor - real identity still unknown... ".
Every night they wake him up, interrogate him further, trying to get him to confess who is he really working for.
After n nights they wake him up again and shout "confess! Mozart confessed already!".