While I assume a cartologist has lost his way and crept by accident into this musical thread, my occasionally weird imagination suggested that a
cartologist might by some stretch be an instrumentalist who drums on
cartons.... Searching for a possibly suitable image, I came across
cajon drums whose origins can be traced back to Africans in Latin America who used old wooden crates to play rhythms on as a means of musical expression. So just for fun - here's a modern version:
And for our next musical letter we have D for drummer