Beatles fans had their own form of Thanksgiving on Nov. 20, 1995, shortly before indulging in their traditional annual meal of turkey, stuffing, cranberry sauce and pumpkin pie. That's when Anthology 1, a double-CD set that was part of a massive historical project, gave the world the band's first new recording since 1970.

The CDs, the first of three volumes, were a collection of rare recordings they had made between 1958 and 1964, beginning with a cover of Buddy Holly’s “That’ll Be the Day” and a Paul McCartney and George Harrison composition called “In Spite of All the Danger.” Many of the other tracks were rooted in Beatles lore.

There were three from their Hamburg-era sessions with Tony Sheridan, five of the failed audition for Decca, two from the successful audition at Parlophone and live takes from the Royal Variety Performance, The Ed Sullivan Show and other televised appearances.

Elsewhere, there were a handful of studio outtakes, such as a couple of attempts at “I’ll Be Back” as a waltz, the demo of “No Reply” and a stunning version of Little Willie John’s “Leave My Kitten Alone” that had inexplicably been left off Beatles for Sale. Also included were clips of the group and manager Brian Epstein telling their story. These were culled from the Anthology documentary, a six-hour oral history narrated by the key participants. The first two hours premiered on ABC two days before the album release, with the other four coming later in the week. But part one concluded with the premiere of the video of the new song, “Free as a Bird.”

Watch the Beatles' Video For 'Free as a Bird'

The original piano-and-vocal recording had been made onto a cassette by John Lennon in 1977. Yoko Ono gave the tape to the three surviving Beatles, who holed up in McCartney’s home studio in Sussex, England in early 1994.

Jeff Lynne, who had worked extensively with Harrison, was hired to produce the record. The process involved cleaning up the original crude recording and overdubbing the other instruments. A b-section featuring lead vocals by McCartney and Harrison was written.

It was a daring proposition for them to undertake, and one that opened themselves up to a lot of criticism. But the Beatles shielded themselves by noting that it was something that happened fairly regularly in the old days. “We took the attitude that John had gone on holiday, saying, ‘I finished all the tracks except this one but I leave it to you guys to finish it all," McCartney said in the liner notes. "And once we agreed to take that attitude, it gave us a lot of freedom.”

Bolstered by a video that contained sly references to dozens of Beatles songs, “Free as a Bird” reached No. 6 on the Billboard Hot 100. Anthology 1 debuted at No. 1 and stayed there for three weeks. Subsequent volumes containing similar Beatles rarities were released in March 1996 and October 1996; Anthology 2 also contained another new song, "Real Love."