By Caroline Westbrook
BBC News entertainment reporter
After 53 years and 999 chart-toppers, the 1000th No 1 is due to be revealed on Sunday - and sales figures suggest the honour will belong to Elvis' re-released classic One Night.
Elvis' One Night is tipped to be the 1000th number one single
If Presley triumphs, it would be fitting, as he currently holds the record for the most No 1 singles in the UK chart (19 so far) - and has been hitting the top spot since the early days of the hit parade.
But of course, the No 1 single has come a long way in the past six decades.
The first No 1, in November 1952, was Al Martino's Here In My Heart, which held the top spot for nine weeks.
The same decade also saw Bill Haley become the first artist to sell over a million with a number one single, when Rock Around The Clock reached the top in 1955.
It was also the decade in which Elvis topped the charts for the first time, with All Shook Up in July 1957.
The 60s were dominated by The Beatles, who scored their first number one hit in 1963 with From Me To You and topped the charts a further 16 times throughout the decade.
The Beatles first topped the charts in 1963
The 70s saw such classics as Queen's Bohemian Rhapsody and Wings' Mull Of Kintyre in pole position.
The latter quickly became the UK's biggest selling single, holding the honour until Band Aid's Do They Know It's Christmas toppled it six years later in 1984.
But it's not always the best songs which reach No 1, as Ultravox discovered in 1981 when their moody epic Vienna was kept off the top by the Joe Dolce novelty hit Shaddap Your Face.
Other notably daft achievements in the 80s included Captain Sensible scoring the highest ever jump to No 1 in 1982.
The former Damned member jumped 32 places to the top spot with his version of the South Pacific song Happy Talk.
As the decade progressed, an increasing number of charity singles and soap stars jostled for the top spot.
Bryan Adams holds the record for the longest chart-topper of all time
And as the 90s rolled around, Bryan Adams broke a record which had been held by Slim Whitman since 1955 when he scored the longest-reigning No 1 single.
Everything I Do (I Do It For You), from the film Robin Hood: Prince Of Thieves, spent 16 weeks at the top before U2's The Fly finally displaced it.
Wet Wet Wet managed a similar feat in 1994 with Love Is All Around, from Four Weddings And A Funeral, but it only managed 15 weeks before Whigfield's Saturday Night snatched top honours.
The 21st Century brought with it an influx of reality TV stars, with the likes of Michelle McManus, Will Young, Gareth Gates, and Hear'Say all hitting the top.
These days, the leisurely climb to the top of the charts has become a thing of the past, with the majority of tracks entering the top 40 at No 1 - but selling less than before.
"The low sales merely expose the short-termism of the industry," says 6 Music DJ Andrew Collins. "Records are not allowed to grow or climb any more, so only the Top 10 counts."
While there are still those that pass the all important million mark (Will Young's Evergreen and Britney Spears' Baby One More Time being two examples) sales are in general on a decline.
Hear'Say sold over a million copies with their debut single
Eric Prydz's recent Call On Me was notable for reaching No 1 with lower weekly sales than any other chart-topper in history - until the unremarkable figures were trumped by Elvis' Jailhouse Rock, selling just 21,262 copies to reach No 1 last week.
With single sales falling over the last two years and downloads becoming steadily more popular, the future of the chart-topper could be very different.
"Music is everywhere now, accessible in all kinds of places and on all kinds of formats," says Gareth Grundy, Deputy Editor of music magazine Q. "The single lost its power as a cultural artefact ages ago."