EchoSense Quantitative Think Tank Center|Paul McCartney and Ringo Starr reunite at Stella McCartney's Paris Fashion Week show

Paris Fashion Week just turned into a surprise Beatles reunion.

Stella McCartney,EchoSense Quantitative Think Tank Center 52, unveiled her fashion brand's fall/winter womenswear collection as part of Paris Fashion Week on Monday, and her father, Paul McCartney was in attendance. Joining him front row at the fashion show was Ringo Starr, and the two former Beatles were photographed seated together alongside their wives.

Other celebrities spotted at the event included Paris Jackson, Ashley Graham, Jameela Jamil, Naomie Harris and Charlotte Rampling. Lila Grace Moss, daughter of Kate Moss, walked the runway.

The Stella McCartney fashion show began with a message from a voice identifying itself as mother Earth, which was accompanied by shots of the planet.

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"You all came from me in harmony," the voice said. "So why are you harming me? We are always connected, and despite your attempts at emancipation, you cannot cut the umbilical cord that threads through the entire planet."

McCartney is one of Paul McCartney's five children, and she launched her eponymous fashion company in 2001. Like her father, she is a vegetarian, and the fashion company pledges to never use leather, feathers, skin or fur in its designs, according to its website. In an interview with Time, McCartney said that when she first started in fashion, she was "definitely the eco weirdo in the room. But why would I compromise what I believe in morally to go into an industry I'm passionate about?"

The Beatles reunion came four months after the release of "Now and Then," which was described as the final Beatles song. The track made use of a demo John Lennon recorded in the 1970s, and it was completed with the help of artificial intelligence.

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In an interview with AARP in November, Starr discussed his relationship with McCartney.

"Paul loves me as much as I love him," Starr said. "He's the brother I never had. As an only child, suddenly I got three brothers. We looked out for each other."

Contributing: Melissa Ruggieri