President's impromptu version has sent sales of the 1971 single through the roof

Sales of Al Green‘s soul classic ‘Let’s Stay Together’ have gone up by almost 500% after US president Barack Obama surprised a packed crowd by singing a couple of lines from the track at a fundraiser in New York last week.

The president cracked out the rendition, which you can see by scrolling down to the bottom of the page and clicking, at the legendary Apollo Theater in Harlem last Thursday (January 19). As a result, sales of the track have been given a huge boost, reports Billboard.

The track, which was originally released in 1971, sold over 16,000 downloads in the week ending January 22, which is a 490% increase from the previous week.

As well as singing, Obama also paid tribute to Green, who was sitting in the crowd, saying: “Don’t worry Rev, I cannot sing like you, but I just wanted to show my appreciation.”

The US president, who is currently campaigning for re-election, is thought to have raised $3.1 million during the day he spent campaigning in New York.