At the 2015 NAMM Show, developer Evan Balster introduced his application Imitone.
Imitone, originally developed as a Kickstarter project, is software that lets you play any instrument with your voice.
It does voice to MIDI conversion, so you can use the MIDI to play virtual instruments.
It’s available for pre-order for Mac & WIndows for US $25. See the Imitone site for more info.