The Beatles’ new single ‘Now and Then’ released

A new Beatles song produced with a little help from artificial intelligence and including the vocals of John Lennon was released on Nov. 2 - to lukewarm reviews.

The song comes more than four decades after it was originally recorded as a demo, but despite the hype left critics distinctly underwhelmed.

"'Now and Then' is not terrible... But ultimately, it's kind of mundane," wrote Geoff Edgers in the Washington Post.

The Times daily in the U.K. said the song showed AI being used to its best advantage.

Parts of it also conjured up "that classic, bittersweet, Beatles-esque flavor" wrote reviewer Will Hodgkinson.

"Unfortunately, none of this can mask the fact that the Last Beatles Song is far from a lost masterpiece," he added.

"'Now and Then' is wispy, indistinct and, frankly, a bit of a wet ballad. It sounds more like late-period Lennon than any moment in the Beatles' career."

Variety magazine took issue with the lyrics in particular.

"It's hard to imagine Lennon being happy with lines like, 'I know it's true, it's all because of you/ And if I make it through, it's all because of you'," wrote the magazine's Jem Aswad.

He said the song sounded more like a "rough and incomplete sketch of a song reassembled and elaborately embellished, rather than a complete one."

"Now And Then", first written and sung by Lennon in 1978, was finished by his fellow band members Paul McCartney and Ringo Starr.

The track was unveiled by Apple Corps, Capitol and Universal Music Enterprises, with a music video due to debut on Nov. 3.

McCartney, 81, announced the song's release in June, in what was dubbed in a promotional trailer "the last Beatles song."

"It's quite emotional and we all play on it, it...