Marx. Source: Imgur. 1550912013 9: 1? PM What' s the difference between a piano, a tuna, and a pot of glue? Y' can tuna piano, but you can' t piano a tuna. I kn Marx Source: Imgur 1550912013 9: 1? PM What' s the difference between a piano tuna and pot of glue? Y' can but you can' t I kn