
"Perhaps one of the most enigmatic musical instruments of all time, The Ondes Martenot ( literally ‘Martenot Waves’) was invented by Maurice Martenot in 1928. The original unreliable tube-based design was refined and later models remained in production until 1988. An interesting overview of the instrument can be seen on Youtube. [
posted here]
"The Ondes Martenot has been used in many film scores first dating from 1931; Odna by Shostakovich, Lawrence of Arabia (1962), Ghostbusters (1984), A Passage to India (1984), through to present day movies such as Amélie (2001) and recently There Will Be Blood (2007) by Jonny Greenwood of Radiohead.
THOMAS BLOCH RETURNS

Thomas Bloch is perhaps the most renowned Ondist in the world ; when great musicians and producers are inspired by the sound of the Ondes Martenot, it is often him they turn to. Radiohead, Tom Waits and Damon Albarn have all worked with him...

LE RUBAN - THE RING CONTROLLER
The most famous is the metal ring, which is worn on the finger of the right hand. The ring is not used when the keyboard is being played, like the ribbon controllers we are used to.

When the Ondes is switched to ‘ring mode’ (au ruban), the ring becomes the sole method of determining pitch ; a very skillful technique, particularly so when you consider that in order to produce any sound at all, you must simultaneously manipulate the clear, lozenge shaped device, known as the touche d’intensité..
LE TIROIR - THE CONTROL DRAWER
The touche d’intensité is a large button on the control drawer of the Ondes Martenot, and is pushed and tapped to produce the tone of the instrument ; in effect , it controls the volume envelope of the instrument. The touche d’intensité is controlled with the left hand while the player uses either the ring or the keyboard to produce the melody.

Next to the touche d’intensité are a series of switches and dials which control the oscillators and create the timbre of the note - as well as send levels to the three loudspeakers.."
The screens:
"Ondes Main Panel
* Send level faders for each of the Ondes Martenot speakers, + line out level
* Faders for each of the 7 oscillators + 'Tutti' switch
* ADSR envelope control ( optional, depending on Setup)
* Brightness control - switchable to 12db Filter with resonance
* Detune, Width and Saturation faders

Ondes Speaker Edit Panel
* Convolution modelling of each speaker
* Close, Far and Room stereo mic positions for each speaker
* 4 different original settings from D2 Spring reverb
* AMP and DECAY settings for each IR processor
Ondes Performance Setup
The Setup Panel is a custom scripted MIDI control matrix. Depending on your playing ability and available MIDI controllers, you can configure the Ondes instruments realtime control options in a number of different ways. See ' Ondes Performance Setup Demo ' video in the Video tab.
* Custom Glide ( Ring) Scripting - realtime control of portamento time
* Control pitch and volume independently using Aftertouch, XY pad or any MIDI cc
* 'Exclude Key ' function - emulate touche d’intensité
* Save User control setups and load to any preset
The Poly-Ondes
The Poly-Ondes is a bonus instrument: a polyphonic synth using the Ondes Martenot oscillators and speaker modelling : create fabulous vintage pad sounds with full LFO and filter modulation, detune all 7 oscillators and play them back through the speakers for an incredibly characterful sound. There are 50 Poly-Ondes presets showing the sound design possibilities."
http://www.soniccouture.com/en/products/g27-ondes/