Shawn Mendes Helps Jimmy Fallon Sing #FallSongs and Performs 'Mercy' On The Tonight Show

What happens when one of the top pop acts in music visits The Tonight Show Starring Jimmy Fallon? Well, Shawn Mendes found out as he visited the show to help Fallon sing some #FallSongs and even performed his latest single "Mercy."

Shawn Mendes covered some of today's best artists in #FallSongs remixes that the Internet contributed to via Twitter. They kicked things off with a little of his his own stuff before breaking into to remixes of Simon and Garfunkel, Coldplay, Naughty By Nature, Adele, Justin Bieber, Mike Posner, Justin Timberlake and The Proclaimers.

He pretty much nailed all of the remixes and some of them could even replace lyrics in the original songs.

During his visit to The Tonight Show, he performed his new single "Mercy" for the crowd in spectacular fashion. Backed with a band under the green lights, Mendes gave a truly genuine performance without any lip syncing involved.

"Mercy" is one of the singles off his new album Illuminate which is now available.

The album features 15 tracks including an acoustic version of "Mercy." You can check out the video's from Mendes' appearance on The Tonight Show Starring Jimmy Fallon below.

Watch Shawn Mendes Sing #FallSongs On The Tonight Show

Shawn Mendes Performs "Mercy" On The Tonight Show Starring Jimmy Fallon

Wanna read more on this? Check these out: Shawn Mendes Drops 'There's Nothing Holdin' Me Back' at Midnight and it's Awesome (Listen) (more); Ariana Grande Performs 'Side to Side' On The Tonight Show Starring Jimmy Fallon (more).