The unusual Conn-O-Sax, an instrument of the 1930’s, is an all metal saxophone in the mezzo-soprano key of F. It has a round ball shaped bell derived from the Heckelphone.

Features that were ahead of its time included the addition of a low A key which was played with the thumb of the right hand, much like what is seen on baritone saxophones today. Even more interesting is perhaps the addition of a high F and a high G mechanism.

Played with a regular saxophone mouthpiece, the Conn-O-Sax was advertised as not only a new addition to the saxophone family but as an instrument that could be used and played in both bands and orchestras as a substitute for the English horn.

As the name suggests, the instrument was built by the C. G. Conn Co. of Elkhart, Indiana.