Question: <https://www.google.com/search?q=western+musical+instruments>

Will it be very few western musical instruments that can be played by human beings with one hand only?

Example : Mouth organ.

Answer: 
Drums. Rick Allen, the drummer with Def Leppard, lost an arm in a car crash may years ago, but has carried on ever since (using an adapted kit, but nothing that any drummer couldn't put together using midi)
Three hole pipe. Usually used in conjunction with a drum to form the pipe and tabor, but the pipe part is a one-hander