Choir Backs Wedding Proposal on London Commuter Train (VIDEO and PHOTOS)

Adam King, 34, thought wedding proposals should go beyond kneeling on one knee - there should be a singing choir on board a commuter train where he would pop the question that would sweep his girlfriend off her feet.

London-based King, who owns a tailoring company, has started as early as April in strategizing his proposal to Lucy Rogers, 26. He talked to a show choir that he sings with, the Adam Street Singers, to make the moment unforgettable to his future bride. Caught on video, the romantic event has become an Internet sensation, still making the rounds a week later.

After passengers of the 19:57 train to Watford Junction had settled in, a passenger in the carriage began singing "Lovely Day" by Bill Withers. Another person sings in, and soon enough, the 25-person choir is into the song, flash mob style. Lucy was amazed by the turn of events, even urging Adam to take a video, clueless that it was all for her.

On cue, Adam knelt before Lucy, showed her an engagement ring, and popped a simple question, "Will you marry me?" Lucy burst into tears and gave her beau a heartfelt "Yes."

Adam later told the Evening Standard that he had to make elaborate plans with the choir because a lot of the members were their common friends, so Lucy should not be able to recognise anyone once they board the train.

Lucy said in an interview that it did not occur to her at all that a proposal was under way.

Asked what made him orchestrate a large-scale proposal, Lucy's boyfriend of six years told ABC News the proposal had to reflect the way she makes him feel.

"Something about her, she really rocks my world," he said.

The video above is available on lucyrog's account on YouTube. It has so far earned over 500,000 hits.