Musical Connection

Exploration Stage: Shooting Star Cabaret
From: Mr. Black
Description: Sophia's dossier still needs to be supplemented. I made inquiries and found out that the singer has an instrument similar to the guitar of a jazzman, who was involved in several crimes. Inspect the instrument for authenticity!
Completed: Keep it up, you have the jazzman's guitar! See, the musician's inscription is on the back: "To Sophia - the talented vocalist of our band." Do you think they were connected by more than music?