by Genevieve Hassan
BBC entertainment reporter
Beyonce performs at President Obama's first Inaugural Ball
When Etta James's song At Last was originally released in 1961, it only reached number 47 in the US Billboard pop chart.
But it was the most downloaded 1960s tune in the US in the past year.
That is in large part because almost 13 million people watched Beyonce perform the track at President Obama's inauguration in January.
And the song became seen as an unofficial anthem for the president, who danced with his wife to the song at each of the 10 official balls honouring his election.
Nowadays it is not unusual for a song that features prominently in the media to suddenly appear in the music charts.
Figures from Nielsen Soundscan also showed Journey's 1981 classic rock hit Don't Stop Believin' was the most downloaded song hailing from the 1980s, beating Michael Jackson's collection of hits.
Why had it been downloaded so many times? The fact the song featured heavily on American Idol this year - both on TV and its live tour - and on new US TV show Glee, undoubtedly helped.
The Cadbury's gorilla helped Phil Collins return to the chart
It is not just the US chart that has been at the mercy of the media, with a similar phenomenon seen in the UK and around the world.
The ease with which music can now be accessed and the inclusion of downloads on the Official UK Chart has allowed old songs to re-enter the chart in a way that was not previously possible.
"This is a perfect example of the immediacy of downloads," says Amy Howard from the UK's Official Charts Company.
"Music is so easily acquired these days you can see something on TV and then go and instantly access it to download."
Tracks used on TV adverts have notably seen re-appearances in the charts - a certain drumming gorilla helped Phil Collins to sell extra copies of his 1981 hit In the Air Tonight, while a group of airport vehicles did the same for Queen's 1979 Don't Stop Me Now.
The Bellamy Brothers' 1976 song Let Your Love Flow, which featured in a credit card advert showing a man going through a town on a water chute, also returned to the chart last year and peaked at number 19 on downloads alone.
Phil Matcham, the Official Charts Company's licensing manager, says you can tell when an advertising campaign is running due to a song's position on the chart.
"Campaigns run in cycles. When the adverts start appearing on TV again, people download the track," he says.
Even songs used in older films are getting a look in.
"It's guaranteed that if Armageddon gets shown on terrestrial TV, Aerosmith's Don't Want to Miss a Thing will chart again. Or if Top Gun is shown, Take My Breath Away will chart," Mr Matcham adds.
But the inclusion of downloads on the UK chart has also enabled non-conventional songs to enter the race.
In the 2007 Simpsons Movie, audiences laughed when Homer Simpson bought a pig and made up a song about it as he walked it across a ceiling.
Becoming a fan favourite, Spider-Pig charted at number 24 as it was available for download from the film's soundtrack.
At just 64 seconds long, it was the shortest song to make the UK Top 75 - a record which was broken three weeks later by the joke 36-second track Ladies' Bras, championed by broadcaster Danny Baker on his radio podcast and which was subsequently made available to download.
The reality factor
Songs featured on TV shows have also affected the public's downloading habits.
A remix of Singin' in the Rain by dance act Mint Royale topped the UK chart in June 2008 after it was used in George Sampson's winning Britain's Got Talent dance routine.
Mr Matcham has seen other reality show trends. "We notice when The X Factor is on we see tracks sung by the main contestants jump up in the chart the following week," he says.
"And when Alexandra Burke won the show and recorded Hallelujah, there were five versions of the same song in the top 200 - purely because she had done a cover."
Alexandra Burke brought the public's attention to Leonard Cohen's Hallelujah
Indeed, when the latest series of X Factor began, tracks by Luther Vandross, Joe Cocker and Kings of Leon enjoyed a second bite of the chart cherry thanks to auditionees offering up their versions.
But can these sales blips translate into actual meaningful success and earn artists great sums of money?
"At the moment, the reality is the number of sales you need to get a high charting entry is not what it used to be," says Jeremy Fabinyi, acting chief executive officer for PRS for Music, which represents songwriters and composers.
"In the good old days a hit single meant a significant amount of money, but at the moment in a bad week you can have a single going into the charts with relatively low actual sales.
"If it's downloads, then the writers may get 8% of a 79p track so you'd need to sell quite a few to get a retirement package." That sum works out at 6.32p per download.
Of course, not every song performed on the likes of X Factor enjoys a return to the chart, but Mr Fabiniyi says there is a relationship between those that do.
"The difference between the ones that lie fallow for a long time and ones that spring to life are the evergreens that go on forever," he says.
"It's a classic case where it all comes down to the song. If you've got a great song it can always live again if you find the right outlet - whether it's an ad, a movie or TV show."