Here is the perfect instrument...with a side benefit.
Here is the LOO-PHONIUM, a combination harp and euphonium. Gary has been wanting to play harp-euphonium duets, and here is the ideal instrument for such duetting.
Gary would, however, occasionally have to get out of the way, and I better remove my embouchure ENTIRELY from the mouthpiece before inhaling deeply.
Gary could also play his part in harp mode (seat up) or in zither mode (seat down).