Music notes: Katy Perry, Noah Kahan and more

Tickets for Katy Perry's concert film Katy Perry: The Lifetimes Tour – Live from Paris are now on sale. Meanwhile, you can watch a mini behind-the-scenes documentary about how the elaborate production came together, plus the sequence from the film when she performs "The One that Got Away."

For several years, Noah Kahan has jokingly complained that he's never been included on one of Barack Obama's playlists, but now his wish has finally come true. After the former president included Noah's song "Doors" on his new summer playlist on Thursday, Noah reposted it and wrote, "I can finally rest." He also reposted the playlist on his Instagram Story and wrote, "And now my watch has ended." That's a Game of Thrones reference that essentially means, "My ordeal is over and now I'm free."

Post Malone has reworked his song "I Had Some Help" for an Aug. 3 Sesame Street special Storm on Sesame Street, which is designed to teach kids how to deal with extreme weather events. After the storm, everyone pitches in to help rebuild, and Posty joins the Muppets to sing "A Little Help," a song about working together to restore the neighborhood.

Workers at a Montreal eatery called Cafe Meekha were shocked this week when none other than Ariana Grande strolled into their establishment, along with her ex, Ricky Alvarez, with who she's rumored to be dating again. She also posed for photos with all the employees: You can watch video of the moment on Instagram. Ari is currently performing in Montreal as part of her Eternal Sunshine tour.