Justin Timberlake disappointed a number of his fans in Buffalo when he cancelled his recent concert.  The earliest he could reschedule was for July, since the Buffalo Sabres will be using the venue to play hockey.  He apologized on Jimmy Fallon and made a promise for his summer show.

Justin and Jimmy also gave a music lesson with their 5th installment of the 'History of Rap.'

First Lady Michelle Obama Appears On 'The Tonight Show' With Jimmy Fallon