What's the most complicated instrument to play (Quora Answer)

To my way of thinking, it is hard to beat the Sarangi. If it wasn't transcendent, there would likely be no reason to maintain such a beast of a violin. Due to the sympathetic strings in its construction, merely tuning it seems nearly a superhuman feat. Among classical instruments, it arguably maxes out simultaneously on depth, beauty, intricacy, and unforgiving difficulty.

The secret to the instrument's continued survival is that it is, to many listeners, the best known mechanical approximation to the human voice.

Note: Arguably the best serious introduction to North Indian classical music is Neil Sorrell's Indian Music in Performance: a Practical Introduction which happens to be built around the Sarangi of Ram Narayan. The entire book disappeared but has now reemerged through a labor of love as a free PDF complete with all the audio files:

http://sarangi.info/2007/02/17/indian-music-in-performance-a-practical-introduction/

including a full transcribed performance. I can't recommend it highly enough.

- Eric Weinstein on Quora