Have learners input notes using only their voice or an instrument of their choice. Once they have their choices, play it back in a loop (it will do this automatically) and play an accompaniment that fits while the loop is playing. If you are working in a particular key, this could work really well for reinforcing that particular key signature. Help reluctant singers find their pitch by seeing if they can make one of the colours light up by either singing loud enough. This function is much more sensitive if the notes played are in tune. It could work for helping singers stay on pitch or for pitch training.
Musicians across all genres of music have heard of Musical Instrument Digital Interface (MIDI). What is interesting, and rather mind-boggling (to be honest), is that music teachers (myself included) trained in university classical music programs either never heard of it or have heard of it but just don't really know what it does. Music educators graduating without modern musician skills and knowledge is an issue discussed in another blog post. Those who have had experience with making music electronically or have dabbled in a bit of recording would possess this knowledge, but mostly those training to be general music or secondary music specialists may not ever embrace this versatile computer protocol.