Barbershop quartet Port City Sound perform / Youtube

The Port City Sound quartet were asked to perform by one of the plane's flight attendants

Every traveller knows there is nothing worse than being cooped up in a plane’s cabin as it waits to get the green light from air traffic control to take off.

Well, for one set of passengers on a flight to New Orleans, the tedium of waiting was made a bit more bearable after elderly barbershop quartet, Port City Sound, gave an impromptu performance of The Drifters’ classic Under the Boardwalk.

The group were discovered after flight attendant Kari Mann started talking to passengers as they waited for over five hours on the tarmac at Indianapolis International Airport. Sensing the growing frustration throughout the cabin, she asked the group to perform.

The Maine-based quartet obliged, bursting into a note perfect rendition of the 1960s classic – to the delight of the their fellow travellers.

Mann, who uploaded the video onto YouTube, wrote online that the song was one of her “best moments” and a “wonderful memory”.

She said: “The mood changed and our passengers were awesome for the whole five hours they were on the plane!”

The video was posted on the 7 January and has since gone viral, receiving over 3 million views in just under a month.