Are music's biggest stars suffering in the top 40 as record labels tweak release dates to fight piracy?
Last week, Coldplay and Kaiser Chiefs surprised fans by releasing new records out of the blue.
Their singles went on sale as soon as they received their first radio play - part of the "On Air, On Sale" strategy introduced by two of the major record labels, Universal and Sony, six months ago.
The idea was to tackle piracy - if a song was available instantly, it would weaken the trade of illegally copied music online.
Record labels say initial research has vindicated the policy, but some artists are not so sure.
While Universal Records has reported a decline in filesharing activity around its singles since January, it has also seen key releases by the likes of Lady Gaga fall short of their expected chart positions.
Judas, the second single from Gaga's Born This Way album, was the sort of song that used to enter the charts at number one.
Instead, it made its debut at 14 and rose into the top 10 seven days later. After that, it disappeared from the top 20 for a fortnight, before peaking at number eight once the video became available.
She is not the only one to see her songs take a rollercoaster ride around the charts - Beyonce, Britney Spears, Arctic Monkeys and Rihanna have also been affected.
Rapper Chipmunk, a Sony artist, complained that "fans don't understand" On Air, On Sale.
"You can't stop someone illegally downloading a song no matter how quickly it goes on sale," he told Digital Spy earlier this year. "The labels should be targeting the illegal downloaders, not hindering the artists."
Even musicians who benefit from the system admit to having concerns.
Girls Aloud singer Nicola Roberts released her debut solo single Beat Of My Drum last week, shortly after it premiered on Scott Mills' Radio 1 show. The 25-year-old engaged in very little promotional activity, with the expectation that awareness of the single would build slowly over a number of weeks.
On Tuesday she excitedly updated her blog, telling fans, "I got to the rehearsal studio to find out my song was number 10 in the midweek chart!
"It's funny how Universal records put out music now," she continued. "They let it be available to download as soon as it goes to radio. The last record I put out with the girls [Girls Aloud], our label didn't work like this at all so it was extra scary for me.
"It's better in terms of illegal downloads but scarier for the artist."
The main argument against On Air, On Sale is that it does not apply across the board.
Two recent chart-toppers - On The Floor by Jennifer Lopez and Unorthodox by Wretch 32 - were released in the "traditional" way, with four weeks' radio exposure before going on sale. Any pre-orders made in that four-week window were counted towards the first week chart position, resulting in a high placing.
Singer Nerina Pallot argues that this gives some acts an unfair advantage.
Her latest single, Put Your Hands Up missed out on a top 40 position despite securing a place on Radio 2's A playlist, guaranteeing up to 20 plays a week.
She says the story would have been different if she hadn't been obliged to put it on sale as soon as it was broadcast.
"Artists like me have a pre-existing fanbase and we rely on them for things like pre-orders," she says. "If my pre-sales had been added up, I would have gone into the top 40.
"It's not a level playing field because not all the labels are doing it. So the public aren't necessarily aware that your single is actually out there to buy."
Jeff Smith, head of music for Radio 2 and 6 Music, agrees that the message is unclear.
"The situation is probably a bit muddy," he says. "It isn't even very clear, even to the industry. I think we're all still getting to grips with it."
He says the main concern is that, while the likes of Coldplay are largely unaffected, the audience needs time to become familiar with a new artist.
"We have very regular discussions with the record industry about release dates," he says.
"We say: 'That record needs a bit more time for people to get used to it before we look at playlisting it.' So although the records might be on sale, and getting played around the station, we'll give an artist a bit of a chance before we come to a hard and fast playlist position."
He adds that, while fans might be perplexed by lower chart positions for Lady Gaga, she has benefitted in the long run.
"You can use On Air, On Sale in a smarter way, and I think you can see that with Lady Gaga. She released two or three tracks to get people used to the concept of the album before it appeared. That gets a little bit of radio traction as well, and it all serves to interest people in the album."
Indeed, despite her wobbly performance in the singles chart, Lady Gaga's album went straight to number one, selling 215,000 copies in just seven days - the highest first-week sales of the year so far.
Meanwhile, as EMI and Warners procrastinate over adopting On Air, On Sale, Nerina Pallot has an idea to stabilise the singles' chart.
"Maybe it would be good to look at the American model of including airplay and general media exposure," she suggests.
"Then we'd get a truer picture of what is a really popular track, what is a fake hit, and what is a manipulated hit."
Additional reporting by Mark Savage.