The Rhodes Mark 1 that was sampled was "prepared" by inserting springs, plastic tubes, pins, etc., inside the piano. These objects when touching the strings or the tines change the sound of each key played. All the notes can be radically different from each other and often you don't even recognize the original sound. The resulting sounds are percussive and unique.
There are 2 main programs, each key has a different sound, the first one covers 72 keys, the second one 52 keys. Each key has a unique sound with up to 6 velocity layers. Also included are 19 patches, each made from one sound mapped across the keyboard. The sample set size is 63.2 MB and contains 367 samples.
It is available in SoundFont and Vsampler 3 formats for $29.99 USD. There is a free SoundFont demo bank and plenty of MP3 audio demos available.