Imagine you're sitting in a pub and Sir Paul McCartney walks in.

That's exactly what happened when he guested on an episode of "Carpool Karaoke." The legendary performer rolled through his hometown of Liverpool with host James Corden, sharing memories of the city, surprising fans in his favorite pub, and bringing all of us a badly needed emotional release with his music.

McCartney's trip down Penny Lane was poignant, and his message of positivity brought James Corden to tears.

The most prevailing themes in The Beatles' music are those of love, peace, joy, and togetherness. It's the kind of music that you put on during the happiest times and when you've had a really rough day.