So many artists, and so many Bluesfest scenes-and one of the unforgettable performers was Lady Gaga.

From OttwaSun, during Canada Day, at the Montreal Jazz Fest, Lady Gaga got on stage with Tony Bennett and sang a duet of 'But Beautiful'.

Tony told Gaga while they're on stage that she is "the best entertainer in the world."

According to some source, the next day after the festival, Bennett tweeted, "How wonderful @ladygaga was to share the stage with me last night at the Montreal Jazz Fest. The audience loved her!"

Lady Gaga replied to the said tweet, "Thank you for the beautiful flowers itstonybennett You've changed my life."

In every concert, it's every fan dream to duet with their idols. During Bluesfest, a dream came true for a 17-year-old

An Ottawa singer was pulled onstage by Lady Gaga during a show in Montreal Wednesday to perform to a cheering crowd.

Fan named Michelle stated:

"I've dreamed of that day for so long,"

"I would envision it for years – so many sleepless nights thinking (of) being on that stage..."

"I didn't know how it would happen or what it would look like but I pictured her face in my dreams."

Watch the video of Gaga and Michelle duet

Michelle saw Lady Gaga almost 11 times and last Saturday's show at Bluesfest was her 12th time. But this time, Gaga came for her to clamber up onto the stage in six-inch heels.

The singer greeted her with a hug and asked, "are you ready?"

Both sang "Born This Way" and audience also hummed and sang the song.