Maybe one of Witchiepoo's henchmen took it.
"T police ask help in recovering $4,000 flute left on bench
MBTA Transit Police are asking for the public’s help in identifying a man who walked out of a Boston subway station with a flute worth $4,000 that a woman had accidentally left on a bench at Park Street station on March 25. The man took the flute and got on the next train, and the instrument has not been returned. Transit police asked anyone with information to call the Criminal Investigation Unit at 617-222-1050. Those wishing to remain anonymous can use the SeeSay app or text a tip/message to 873873."
Also see: Boston Globe Hits a Sour Note