Guillaume Toutain is a musician who builds variable pitch drums. He is the inventor of the Keytam, a melodic drum that functions similarly to a talking drum. The Keytam evolved from the Jogad'oc which he built as a variable pitch tambourine.
Keytam Youtube 1)
Keytam website 2)
Toutain's Youtube channel 3)
Interview (in french) on the Jogad'oc and how it works 4)
A comprehensive video explaining how the various mechanisms on his instruments work 5)
Toutain has made two related instruments the Jogad'oc and the Keytam.
This instrument is the precursor for the Keytam. It is a tambourine with a mechanism that tightens the edges of the drum head allowing for the pitch of the drum to shift. The drum head has two small felt pads adhered near the edges allowing for it to generate a lower pitch then would normally be possible with a geometrically consistent drum head. 6) There is also a snare that can selectively be depressed to add the timbre of a snare drum. This instrument also sometimes has small magnets added and moved around the drum head to add another change in the timbre.
The Keytam has a number of features added to the tambourine form found on the Jogad'oc. The Keytam has the pitch bending mechanism added at the end of a wooden arm that extends off the drum, this allows the instrument to be played in a similar position to the guitar, and allows for a more ergonomic position while being played. The mechanism for pitch bend is similar to the prior version but includes a lock that allows any pitch to be locked in place as well as a lock for the snare to lock the snare into various positions. Both instruments feature a set of jingles chimes on the tambourine but the Keytam has the jingles on a separate loop of wood that allows for them to be adjusted.