Hello everyone, I'm addressing my friend Lionel in particular, who gave a very good answer. However, where I don't quite understand you, Lio, is when you talk about polyphonic and monophonic voices. I think everyone understands polyphony, which literally means "several sounds or voices". Monophonic, on the other hand, means "one voice". Now, if we take the system of musical reproduction that consists of distributing sound in space, the simplest is called STEREO (two channels), whereas MONO (phonics) reproduces all sounds on the same channel, mixing them.
So, in stereo AS IN MONO, there are several sounds, which we could call polyphony. However, I think, Lionel, that what you really mean is that AMAZING software can transform a single AUDIO voice (MP3 or Wave...) into midi.A single voice, in other words, a single instrument such as a guitar, trumpet or saxophone.
But can it transform the piano, which alone comprises 2 voices (left and right hands) unless you mix them together, and what about a drum kit comprising several instruments? In any case, thank you for your always useful and judicious insights. Best regards Serge a