Derringer + a musical instrument = musical death

[Berrik]

Pretty much as stated. Combine a derringer and a vuvuzela or a derringer and a saxophone and there will be no indication you have it until you fire it, which also plays the instrument as normal. Mabye add some wiring or something to rig it up if need be. Examining the rigged musical instrument when it's in your hand or on the floor will reveal it, but not if it's in someone's hand.

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BOLD BULL shoots Einstein at point-blank range with the vuvuzela!