small musical instrument played from the 12th through the 16th century, popular for secular music. It had one rank of flue pipes (producing a flutelike sound), sometimes arranged in rows to save space, and was slung from the player's neck by a strap. The keys and pipes lay at right angles to the player, who used two fingers of his right hand to play melodies. With his left hand he worked a bellows at the back of the instrument. Except for occasional drones (sustained notes played against a melody), the portative organ played music consisting only of a melodic line. Its compass was from two to three octaves.