Monsieur Gauguin takes his organ through its paces.
Photo purportedly taken by Alfonse Mucha, in his studio. So I guess it's entirely possible that it's Mucha's organ he's fiddling with. Can you imagine Mucha's surprise?
You sir are sans pantalon! Unhand my organ!.
[Pic via Vintage Photographs, schoolboy 'organ' references by me.]