WATCH: Katy Perry begins her new world tour, "Witness: The Tour"

The first show of Katy Perry's fourth world tour, "Witness: The Tour", took place yesterday (9/19) in Montreal, Canada. The show was a spectacle for the eyes, with many special effects and an incredible structure.
The show began with the theme song from the album, Witness, where Katy appears floating on a star during her performance. The show continued with "Roulette", in which in interview for Billboard, Katy says to be a big performance, that counted on some giant data on the stage and with several choreographies.

Dark Horse was the third performed song, with much choreography, visual effects and without the part of Juicy J, as it happened in the "Prismatic World Tour".

Then came "Chained To The Rhythm", with a version already seen in the previous shows, finalizing the first act of the show.

The second act of the show was "Teenage Dream", "Hot N 'Cold", with a rock version, "Last Friday Night", "California Gurls", with the "Left Shark" and "I Kissed a Girl".

With "Déjà Vu", "Tsunami", "Bon Appétit" and "E.T.", Katy performed the third act of the show.

In the 4th act of the show, Katy sang "Thinking Of You", flying over the arena on a planet. Then she also performed "Save As Draft", in the Drop Zone, and "Power".

Katy returned to the stage with "Hey Hey Hey" on a motorcycle, in which she moved throughout the show. Soon after, the singer performed "Part Of Me", "Swish Swish", where she performed a "basketball game" with a fan, and "Roar".

The show ended with the song "Firework". The next show of the tour takes place on September 21 in Connecticut, United States.