Why change a successful formula?

That's obviously the motto of director Rachel Kavanaugh whose revival of Rodgers and Hammerstein’s evergreen classic Oklahoma! serves up big helpings of the much loved boot-stomping dancing and singing routines.

It met with the full approval of the Congress Theatre audience despite the corny storyline and thick cowboy drawl.

When this folksy musical premiered back in 1943 few thought it would be such a big hit, but it has survived the test of time, with numbers like Oh, What A Beautiful Mornin', People Will Say We're In Love and the title song still hugely popular.

It helps tremendously that the four leads, Ashley Day, Belinda Lang, Charlotte Wakefield and Gary Wilmot, all have excellent voices.

Day gives handsome hero Curly equal amounts of charm and cockiness as he woos Wakefield's fiesty Laurey and has a dramatic showdown with brutal love rival Jud Fry (an impressive Nic Greenshields).

Cheeky chappie Wilmot is superb as cunning Persian peddler Ali Hakim, and Lucy May Barker's Ado Annie is a delightful floozy. Lang adds to the fun but could be stronger as croaky old Aunt Eller.

Choreographer Drew McOnie stretches the imagination with a dream ballet sequence featuring burly cowhands.