A brass wind instrument that can be best be described as the marriage of the French Horn and Euphonium. It produces a sound so lofty and aristocratic, that it sounds quantifiably holier that its counterparts in the brass wind instrument family.
For the true effect of this instrument to be unfurled to the audience in full regalia, the player is recommended to periodically dart a derisive sidelong glare with arched eyebrow at the other non-sanctiphoniums in the orchestra to achieve the desired effect.
One by one, after only 3 minutes into the Bach piece, all of the players in the chamber ensemble save for the lone Sanctiphonium got up in a huff and left in mid movement, leaving the lone woodwind to wallow happily in it's own self-satisfaction.