The oboe is an item in Problem Sleuth. Though it could have easily been added to anyone's inventory, nobody bothered to actually pick it up.
The instrument was initially found in the Speakeasy, wedged between the still room and jazz room doors. This meant neither door could be opened from within. The amount of Vim required to remove the oboe is somewhere between that of Ace Dick and Fiesta Ace Dick.
Clubs Deuce has also been seen playing an oboe.