Even the most casual of viewers of 'The Tonight Show Starring Jimmy Fallon' are well aware of the host's emphatic love for music. Neil Young remains one of Fallon's favorites, as he's done his impression several times over the years -- and his imitation of the rock and roll legend is pretty dead on.

On his most recent stop on the 'Tonight Show,' Young allowed Fallon to live out his fantasy of "being Neil Young" as the pair performed a duet on Young's 1972 classic, 'Old Man.'

As Young is introduced, he is seen sitting alone with his acoustic guitar, cowboy hat, long hair and ... wait! That's not Neil, that's Jimmy, and he's doing an admirable job. Then finally, at just under two minutes in, the man himself ambles onstage, dresses identically to take over the song. The two harmonize through to the end for one very special performance. Though his age may show on his face and his scalp, Young's voice is as strong as ever.

Young returned to the stage backed up by house band the Roots for a storming and passionate take on 'Who's Gonna Stand Up?' from his new album 'Storytone.' Check it out below: