A British family of six has become an online sensation with their coronavirus self-isolation rendition of the Les Misérables song "One Day More." The Marsh family from Kent, England, reworked the song to list the frustrations they've felt while stuck at home during the U.K.'s nationwide, three-week lockdown, which is only half over and may well be extended.

The video has been viewed 7.5 million times on Facebook. Dad, Dr. Ben Marsh, told CBS News it was originally uploaded for family and friends to see, but it was quickly shared around the world. The family were taken aback when the clip went viral, as March said they had "absolutely no clue that it was to catch fire," and they've been "overwhelmed by the response."

This is the last one we are going to do on a lockdown theme, but it felt very apt. And it might be just in time to cheer up some friends and family who have had - or are about to have - birthdays, all by themselves. Decided to include a bit of the intro so that you can see what kind of madness Danielle Marsh and I would be dealing with, if we didn't occupy them with music making...Hope everyone out there is doing okay. Posted by Ben Marsh on Sunday, March 29, 2020

Mom Danielle sings about the struggles of trying to get an online shopping delivery slot from a grocery store. Thomas, 12, and Ella, 10, sing about missing their grandparents: "They are miles away. They can't work Skype! We're broken hearted." While Tess, 8, sings about the struggle of sharing devices with her brothers and sister.

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At the beginning of the video, as the performance is about to start, a small sibling squabble breaks out between Thomas, 12, and Tess, 8, about making too much noise and annoying each other throughout the day — the strain of constant companionship clear to see.

The Marshs never intended to follow their performance with others on the lockdown theme, but since the video has been so popular, Marsh told CBS News they'd been, "persuaded that music, kids and sharing home footage can keep us moving and offer a bit of light relief from scary times."

The family have received lots of positive messages from people around the world, with some 62,000 comments on their Facebook video. Many come from front-line health workers and even people in hospitals who say it helped cheer them up.

Marsh said knowing the video has made others smile is the best contribution his family can make to the world right now.