It would stand to reason that late night talk show hosts would be so competitive with one another that they'd avoid appearing each other's shows. Such was not the case for Jimmy Fallon of 'Late Night With Jimmy Fallon' and Jay Leno of 'The Tonight Show.' There is no late night war between these two. Not only did the always-funny Fallon graciously drop by Leno's show on Thursday (Nov. 17), he shared some trade secrets, such as the subtle differences in his Neil Young and Bob Dylan impressions.

Fallon revealed that they key difference between the two titans of classic rock lies in the harmonica, not their vocals. Fallon pointed out that Young pays attention to tuning and adopts a tuneful approach when handling the instrument, whereas Dylan is more random and sort of just blows into it. A-ha! So, that's the ticket.

Fallon then proceeded to demonstrate his famous and gut-bustingly funny cover the 'Fresh Prince of Bel Air' theme song in falsetto a la Young, while strumming the acoustic guitar and carefully using the harmonica. A rap song was seamlessly and hysterically transformed into a rock tune courtesy of the multi-tasking Jimmy Fallon.

Watch Jimmy Fallon Explain His Neil Young + Bob Dylan Impressions