The Jonas Brothers transform "I Want a Hippopotamus for Christmas" into a boy band song and "Ironic" into a Broadway song in the latest rendition of Musical Genre Challenge. The Tonight Show Starring Jimmy Fallon. Stream now on Peacock: https://bit.ly/3gZJaNy Subscribe NOW to The Tonight Show Starring Jimmy Fallon: http://bit.ly/1nwT1aN Watch The Tonight Show Starring Jimmy Fallon Weeknights 11:35ET/10:35c Get more The Tonight Show Starring Jimmy Fallon: https://www.nbc.com/the-tonight-show