For all the Mercury Prize’s nods to populism (Arctic Monkeys, M People), novelty (Pulp) and pointless obscurity (Talvin Singh), sometimes it succeeds in its mission to popularise hitherto marginalised music. Hence, Elbow, a band who, after three albums of unfairly unheralded toil, needed and unapologetically wanted to win the prize.

As a result, the wider world has awoken to the many charms of the Bury quintet. Whereas before what leader Guy Garvey described as “the best thing to happen to us” they might have been grateful to fill the Roundhouse once, last night was the second of three sell-outs.

And whereas for most bands the phrase “this is a track from our new album” results in their audience filling glasses or emptying bladders, erstwhile Elbow staples such as The Stops or Scattered Black And Whites passed by almost unrecognised, but anything from the Mercury winner The Seldom Seen Kid was greeted with joy and wide-eyed reverence.

Wisely, laurels are not being rested upon and Elbow are discovering that they love being loved. Halfway through, Garvey dedicated Newborn to a heavily pregnant woman in the circle.

More than that, he changed the song’s first line from “I’ll be the corpse in your bathtub” to the more baby-friendly “I’ll be the duck in your bathtub” for her and ordered the crowd to turn and serenade her. As acts of spontaneous loveliness go, it was perfect. Later, after the magnificent One Day Like This ended with a shower of balloons and festive glitter, Garvey promised to return for an encore only if the crowd repeatedly sang Happy Birthday — rather than the usual “more” — to one of his string quartet. They did: of course they did, just as they couldn’t help themselves but cheer wildly when Garvey accidentally on purpose uttered the word “Mercury”.

If Garvey is approaching national treasure status, his band’s newly appreciated music remains as stately as ever, but for all the warmth and uplift of their shows, they still sing of death, alcoholism and betrayal. The big ballads, especially The Loneliness Of A Tower Crane Driver, had their own luminous beauty, but Elbow can rock too: Weather To Fly began in acoustic gentleness and concluded in symphonic wonder.

Elbow have gloriously seized their moment. All that remains is to eclipse The Seldom Seen Kid. Only a fool would bet against them.