Ondes Martenot

The Ondes Martenot is an early electronic musical instrument, invented in 1928 by French cellist and radio telegrapher Maurice Martenot.  Most models include a dummy keyboard that is used with the ring controller and an actual keyboard that has some lateral movement, allowing the player to play vibrato either way.

Cantos acquired its instrument (a 1975 model with three diffusers) in 2008 from French dealer Jean Michel Renard after a decade-long search.

Pop Culture Reference
Considered the first orchestral/concert electronic instrument . Musicians who composed for the Ondes Martenot include Messiaen and Varèse.  This instrument is also used extensively by rock band Radiohead.