After months of anticipation, the highly awaited "final song" by the Beatles, titled 'Now and Then,' was released.

This historic musical collaboration, bringing together the talents of John Lennon, George Harrison, Paul McCartney, and Ringo Starr for one last track, was made possible through the application of artificial intelligence (AI).

'Now and Then' is rooted in a 1978 demo by John Lennon, the Beatles' iconic frontman who tragically lost his life to an assassination in New York City in 1980.

The initial efforts to work with John’s "Now and Then" demo date back to the mid-'90s when Paul, George, and Ringo reunited with the objective of crafting "new" songs for inclusion in the group's Anthology albums.

They successfully completed "Free as a Bird" and "Real Love," seamlessly integrating full-band arrangements with John’s original demos.

The Challenges

However, their progress on "Now and Then" eventually hit a roadblock due to technical challenges, primarily stemming from the intricacies of the original tape.

The difficulty arose as John's piano often overshadowed his voice in the demo, and the technology required to separate the two elements was lacking at the time.

Paul said in a new mini-documentary about the song:

“In John's demo tape, the piano was a little hard to hear. And in those days, of course, we didn't have the technology to do the separation. Every time we wanted a little bit more of John’s voice, this piano came through and clouded the picture."

Consequently, the session involving the remaining three concluded without ever completing "Now and Then."

The Solution

However, the moment came in 2021, working alongside the creative and technical team responsible for the Lord of the Rings trilogy, the same team that contributed to Peter Jackson's 2021 Beatles documentary, "Get Back," a clean extraction of John's distinctive voice became achievable.

Director and Producer Peter Jackson said in the documentary:

“During the course of 'Get Back,' we were paying a lot of attention to the technical restoration that ultimately led us to develop a technology which allows us to take any soundtrack and split all the different components into separate tracks based on machine learning."

Finally, 'Now and Then' could be brought to fruition.

In June, Paul offered a glimpse, hinting at the impending release of a final Beatles song crafted with the aid of AI technology trained to recognise the unique voices of the band members.

Notably, generative AI audio models had gained recognition previously for their involvement in unofficial "collaborations" and remixes, exemplified by the AI-generated song "Heart on My Sleeve," which emulated artists like Drake and The Weeknd, and a remix of The Weeknd's "Starboy" featuring an AI-generated version of Selena Gomez.

Ringo mentioned that he and Paul recorded new drum and bass tracks to complement the updated recordings of John and mixes of George, who passed away in 2001.

However, during the development of the new song, the true nature of the project had to be kept under wraps from other musicians brought in to add instrumentals.

The documentary providing insight into the song does not delve into the specifics of what to expect from Geroge's past recordings on the completed track.

It has been mentioned that he was not particularly fond of the unfinished John song initially, but Paul affirmed that they retained his contributions from the Anthology sessions, and Paul himself contributed a slide guitar solo in Geroge's distinctive style.

Despite some initial concerns from fans, all parties involved in the project, including the estates of the deceased band members, appear to be entirely satisfied with the manner in which "Now and Then" was brought to life.

Even if this marks the ultimate chapter for The Beatles, the prospect of using this track separation technology to restore and rejuvenate countless recordings, some predating the Fab Four, is an exciting one to ponder in the years to come.