Music icon Paul McCartney reportedly delivered a rare performance of The Beatles' classic "I Want to Hold Your Hand" at the wedding reception of Taylor Swift and Travis Kelce.

The event, held on July 3 at Madison Square Garden, saw McCartney perform a song he had not played live for an audience in decades.

According to a source who confirmed the detail to USA TODAY, McCartney's rendition of the 1964 hit was a significant moment for guests.

The song, which was instrumental in launching Beatlemania in America, was last performed by McCartney with The Beatles at the Paramount Theatre in New York on September 20, 1964, as noted by Setlist.fm.

This makes his recent performance a truly unique occasion for the attendees.

The relationship between Swift and McCartney spans over a decade, with Swift recently praising him as "eternally exceptional." Their shared history includes a joint performance at the 40th-anniversary celebration for "Saturday Night Live" in 2015, and an interview for Rolling Stone's Musicians on Musicians issue five years later.

Adding to the star-studded musical lineup, Stevie Nicks also performed at the wedding, a source told USA TODAY.

The specific songs Nicks performed remain undisclosed.

Nicks and Swift have a long-standing connection, having performed together at the 2010 Grammy Awards and collaborated on liner notes for Swift's album, "The Tortured Poets Department." Swift has previously spoken about Nicks's influence, describing her as having a "magical, wonderful, wise approach to life."

Representatives for both McCartney and Nicks have been contacted for comment.