Several answers come to mind: found it, stole it, fell off the back of a cart—

But no, those are not quite right.

He does preface his answer with the offer of a handkerchief. (Mostly clean.)

"I traded several goats for it, and a few other things," Aleksei creaks. "I might have paid too much, but the craftsmanship seemed very fine even to a know-nothing like me."

Slowly, Aleksei looks around the room, then sighs.

"My wife will be so dismayed if I come home with no coin. Perhaps we can make a bargain for your beloved instrument?"