The Marxophone is a musical instrument that has four sets of chord strings (Cmajor, Gmajor, Fmajor and D7) to be strummed with the left hand and two octaves of double melody strings (Cmiddle - C'') which are struck by metal hammers activated by the right hand. The hammers are mounted on spring steel and produce a mandolin-like sound from repeated bouncing on the strings, hence the name mandolin-guitar-zither that was sometimes applied to the Marxophone.
Mr. Marx was one of a number of late 19th century/early 20th century musical gadget manufacturers who would combine two or more instruments into one: the Hawaiian ukelele and the bowed violin or the mandolin-guitar-zither yielded instruments with strange names like the Ukelin and the Marxophone. Other inventions included the Banjolin, the Hawaii-Phone, the Mandolin-Uke, the Marxolin, the Pianoette, the Pianolin, and the Tremoloa.
Marxophones were billed as easy-to-play and sold on time-purchase plans by door-to-door salesmen as well as through mail-order companies such as Sears. The 1902 Sears catalog called the Deweylin Harp, a precursor of the Marxophone, "...the wonder of the age" and "...the greatest musical instrument that has ever been placed before the public." These mandolin-guitar-zithers combined three instruments for the price of one.