Have a listen to some of the unusual instruments that I came across lately.
Here´s some info to each instrument, followed by a link to the original video.
#1 Factory Fan Bass: By attaching a disk with holes to the fan, it converts blinks of lights to electric signals and generates sound from a bass amplifier. Different numbers of holes can generate a musical scale, and turning on/off of the power makes it roar.
https://www.youtube.com/watch?v=omgbhGirTtY
#2 A nyckelharpa is a traditional Swedish musical instrument. It is a string instrument or chordophone. Its keys are attached to tangents which, when a key is depressed, serve as frets to change the pitch of the string.
(no source)
#3 The hammered dulcimer is a percussion-stringed instrument which consists of strings typically stretched over a trapezoidal resonant sound board.
https://www.youtube.com/watch?v=E6QOr-oCTwU
#4 The sador is the synthesis of the lute, the Indian sitar and guitar.
https://www.youtube.com/watch?v=wyf7cZkpnBo
#5 Two Arduinos are used as capacitive touch sensors, which deliver a midi signal.
https://www.youtube.com/watch?v=G6qVIxaDYDI
#6 The Carnyx, is a wind instrument of the Iron Age Celts, used in warfare between 200 BC and 200 AD.
https://www.youtube.com/watch?v=-DIIaCUJ1yQ
#7 DIY PVC pipe xylophone
https://www.youtube.com/watch?v=NIXt8lU-OIQ