My plan is to use it 98 percent of the time as a piano. My current keyboard has other voices. Not many a few strings and organs. I've never used any of them. I like playing the blues, so if the new piano I get has a sax or an interesting horn I might try it for some blues songs, but that would be about it. As far as polyphony goes I'm only planning on playing songs from sheet music one at a time. Nothing fancy. I googled what polyphony meant. It went over my head. I don't know if it's important to get the sound I want from a budget keyboard.