Should the unthinkable happen, and a grassroots campaign by Jeff Buckley fans disrupt Simon Cowell's efforts to again secure a Christmas number one, BBC Radio 1 will be forced to deal with a tricky issue of protocol. Normally, the station interviews chart-topping artists before playing their winning song (even when Bob the Builder won, Neil Morrissey stood in). But Buckley would be sadly unavailable for selection.
The supremely gifted singer, whose haunting rendition of Leonard Cohen's "Hallelujah" has reignited public interest in the pop charts, died in a swimming accident on 29 May, 1997. He had completed just one studio album, and was on the verge of major celebrity when his life was cut short.
Today, Buckley boasts a cult following. His album, Grace, is considered one of the greatest records in pop history. Rolling Stone recently put him at 39th, one spot below Elton John, in its list of the "100 greatest singers of all time".
He is also extremely influential. A generation of musicians, from P J Harvey and Rufus Wainwright, cite him as a major source of inspiration. Justin Timberlake called his dog Buckley, by way of a tribute. Brad Pitt recently appeared in a documentary about his life.
Yet Jeff Buckley's real legacy lies behind a smartly-painted door of a small house in the bohemian Los Angeles suburb of Silver Lake. This is the home of Mary Guibert, a woman who has painstakingly safeguarded his reputation ever since the day he was killed in Wolf River Harbour, Tennessee. Ms Guibert knew Buckley better than anyone: she was his mother.
"I think Jeff would have found this number one thing very amusing," she said, during a break from writing Christmas cards yesterday. "It's ironic in so many ways. I mean, here is The X Factor, run by Simon Cowell, who is supposed to be the ultimate taste arbiter, and they've been run to the wire by my son.
"It's come about so organically, with no record label pushing it, and I think Jeff would have loved that, and loved his fans for doing it."
Buckley's father was Tim Buckley, a folk musician in the Bob Dylan tradition who had met Mary at high school in Orange County, a region of California often described as the Essex of Los Angeles. She became pregnant with Jeff in 1966, just as Tim Buckley's career was taking off; they were divorced soon afterwards.
"When I was 17 and pregnant with nothing to do I would sit at home and eat spaghetti and play Chopin on the piano," says Ms Guibert. "I was a concert pianist. Before he was even born, he spent months pressed up against that piano, listening to music."
Jeff never met Tim until 1975, when at the age of nine he was taken to one of his concerts in nearby Anaheim. Mary says the event caused him to "fall in love" with his father and "absolutely guaranteed" that he would follow in his footsteps as a musician.
"From that day, it took the form of a moral imperative for Jeff to be a musician. When other kids were watching television or on the phone, he would be in his bedroom listening to records by Hendrix or Led Zeppelin, and playing guitar."
But Buckley didn't get to know Tim. A couple of months after their first meeting, his father died from a drug overdose. Mary meanwhile married and divorced again, condemning her son to a youth she once described as "rootless trailer trash".
"There was always something a little melancholy about Jeff's observation of the world," says Ms Guibert.
"When he was four or five he would come up and say 'why are people so mean to people?' In childhood, he observed a lot of man's inhumanity to man, or rather man's inhumanity to woman."
After leaving school, Buckley studied guitar at the Musicians Institute in Los Angeles, before hitting the road to travel America playing in small venues and coffee shops. The breakthrough occurred, or so the legend has it, after moving to New York in 1990.
Shane Doyle, the owner of a small coffee shop called Sin-e in the East Village, hired him to play at the venue each Monday night, to a crowd of regulars who included William Burroughs and Lou Reed. Soon the gigs were the talk of the town.
"Very quickly, it became clear that this guy was seriously good," he recalled yesterday. "We were a tiny venue, very untidy, and I'd be getting these phone calls asking me to reserve a table for famous producers like Clive Davis or Seymour Stein." Buckley could hit notes across a range that spanned eight octaves. His guitar playing, on a 1976 Gibson Les Paul, was accomplished. Although he often played covers (he was a relative latecomer to the art of songwriting, and wrote relatively few original tracks) he was swiftly heralded as a singular talent.
In 1992, after a bidding war that reputedly ended in a $2m (£1.3m) contract, Buckley was signed by Columbia Records. His debut album Grace was released in 1994, after which he began a national tour.
Grace included the cover version of Leonard Cohen's "Hallelujah" which would become Buckley's most famous record. In person, despite the melancholy nature of his music, Buckley was extroverted, and renowned as a gifted mimic. Buckley's biographer David Browne said: "He grew up thinking of himself as an essentially unattractive individual, so when he signed to Columbia and had girls swooning over him, sure – he took advantage.
"He also dabbled with heroin. It was in the mid-1990s when it was a cool drug, during this period when he looked up a lot of his father's old friends, and tried to pick their brains and understand his father."
Yet the incident that ended Buckley's short and glorious career had nothing to do with rock 'n' roll excess. It occurred on a hot evening, when he took a break from recording his second album at a studio in Memphis to go for a swim in the Mississippi. A swirling current carried him downstream. His body was discovered several days later.
When Jeff's death eventually sunk in, Ms Guibert dedicated herself to securing her son's legacy. She oversaw the release of his almost completed second album Sketches for My Sweetheart the Drunk.
More recently Ms Guibert has compiled several other records of live recordings that have sold millions of copies around the world. Today, she also helps run the countless fan clubs that still organise dozens of tribute events around the world on his birthday each November.
A film of his life is currently in development, produced by Michelle Cy – who produced Finding Neverland – and Orian Williams, the producer of the recent film Control, about another singer who died just when they were beginning to emerge, Joy Division's Ian Curtis.
It should be a compelling narrative, steeped in the glorious musical tradition of talent cut that is short in its prime.
"If Jeff had lived, he would now be on a level with Bono," adds Ms Guibert. "He would have toured the world and had a lifelong career, and at the end of it, he would have been that guy sitting in a wheelchair with the microphone specially lowered six inches, so that we could all hear him sing "Hallelujah" one more time."