MIDI Choir

This Application will take a single-pitched audio source and transpose it in real time according to the supplied MIDI notes. My main motivation to create MIDI Choir was to be able to sing harmonies live, however the product may also be used for studio work. Below are some of its key features.
Reliable ASDF pitch tracker with voiced/unvoiced recognition

• Pitch tracking indicator
• Separate processing of voiced vs. unvoiced input, thereby preserving a natural, intelligible sound
• Voiced input will be re-pitched according to the keys pressed
• Polyphony with unlimited number of voices
• Octave, semitone and fine tunig controls
• Built-in noise gate with indicator
• Built-in soft knee limiter with color-coded LED indicator
• Built-in stereo reverb with controls for room size, damping, stereo width and dry/wet mix,
• Master volume control with output clipping indicator
• Effects may also be used without MIDI input
• Option of VST plugin or stand-alone executable

http://vicanek.de/audioprocessing/midichoir.htm