Jimmy Fallon returned to NBC's "The Tonight Show" on Monday night. It was nine days after the death of his mother, Gloria Fallon. Needless to say, the host became emotional as he talked about her. He shared that his mom was his best audience. It was her that he always tried to make laugh. Instead of a funny monologue, he told a very precious story about her. He said they would squeeze each other's hand three times and say, "I love you."

Fallon's mother died on November 4 at the age of 68 from an undisclosed illness. Therefore, all the scheduled shows last week were canceled and replaced with reruns so Jimmy could be with his family members during their time of bereavement.

First night back

On Monday night, Jimmy made sure he thanked everyone for their support while he was off. Taylor Swift was not scheduled to be on the show, but she showed up to surprise Jimmy and to support him on his first night back in the studio. The show's writer and producer Mike DiCenzo explained on Twitter that the singer agreed at the last minute to appear and perform for Jimmy. NBC wanted something special for the first show back. Swift was already in town for "Saturday Night Live." Without hesitating, she said she would do it.

DiCenzo also shared on Twitter that it was a rough day for the entire staff because they all knew and loved Gloria Fallon, and she loved them and the late night talk show.

Taylor Swift's performance

Swift surprised Jimmy's audience by appearing and singing a song from her new album, "Reputation" for the first time.

The song was a ballad called "New Year's Day." The words were written before Fallon's mother died, but the lyrics were similar to the childhood story Jimmy had just told. Swift sang about love and loss and about someone squeezing her hand three times. The performance moved Fallon so much that he gave Swift a lingering hug after the song was over.

People in the audience were tearing up during the performance as they listened to the words and remembered what Jimmy had said at the top of the show in his tribute. The Roots’ drummer Questlove tweeted about Swift's song. He commented that the lyrics were so similar to what Jimmy had shared. He concluded that you just can't make up things like that.

Hosts and many other Celebrities offered support for Jimmy. Carson Daly posted on Instagram on Tuesday that his mother and Jimmy's mother were dear friends. Carson said he knows what Jimmy is going through because his mother Pattie Daly Caruso died in September.