Taylor Swift's London Eras Tour stop was so star-studded that even Beatles legend Paul McCartney showed up.

In a viral video, McCartney was even seen having the time of his life dancing with fans during Swift's concert.

According to the video's caption, McCartney left the VIP box to interact with fans.

The iconic singer was seen busting some moves with a group of girls wearing glittery skirts and the Eras Tour's signature friendship bracelets stacked on their arms.

READ MORE: Prince William Thanks Taylor Swift for 'Great Evening'

One fan tweeted the video and said, "I find it so endearing that Paul McCartney is truly the most legendary person to attend eras tour and also the only one that openly went into the crowd to vibe with them."

Many people pointed out that McCartney may have been reminded of BeatleMania while attending the concert due to Swift's passionate fans and large crowds.

"I think this moment of getting to be on the other side safely during a very Beatles mania type situation was probably incredible for him. I love that he got to experience what joy he brought to so many," one person tweeted in reply to the video.

"I wonder if he feels like this is similar to the [Beatles] fame or how it feels different," another person wondered on TikTok.

"Paul McCartney loved beatlemania and he loves whatever cult thing [Swifties] got going on too," another fan tweeted.

Another fan on TikTok shared that one of the girls seen in the video is also a Beatles fan.

"The girl in the pink hat is called Erin (twitter: redlipclassic) & like last week was posing next to a statue of Paul & the rest of the Beatles in Liverpool, now look at her dancing with him!!" they shared.

SPOTTED: Celebrities Having a Blast at Taylor Swift's Eras Tour

Let's take a look at all of the famous Swifties that were spotted in the stands.

Gallery Credit: Danielle Kootman