This video demos the Tapehead Inspector – a sort of tangible sampler. 

Here’s the background on it, via Roy Mohan Shearer:

Inspired by the reversal of the name of a musical trio that I play in with Chris Croasdale and Mr. Jonnie Common. We’re really into tapes, and as Chris’ birthday was coming up Jonnie and I decided to make him a wee instrument: A manual tape player, ie. one in which the player can directly control the movement of the tapehead against the audio tape.

Simply a hack of the increasingly hard-to-source cassette walkman, I took out all the mechanics, hard-wired the tape circuit to ‘on’, lengthened the cable to the tapehead and housed the whole thing in a videotape casing. Jonnie built the instrument case/playing surface and then we made up a few audio tape ’slides’ by recording some of Jonnie’s choice vinyl to tape and getting crafty with scissors and sticky tape! I am abridging greatly for brevity here – I maimed one walkman making the whole thing work and the overall instrument design was chewed over a few times over cups of tea at Jonnie’s house. We’re pretty pleased with the results and hope Chris enjoys inspecting his tapes!

Looks like this would be fairly easy to recreate – and an interesting, tactile way to manipulate sound.