Atmosphere alone can't make a show, but enthusiasm and colorful trappings certainly keep it exciting. From yards of festooned fabric that simulate a circus tent to a hazy glow giving the lights a magical quality, this eye-catching revue is an energy-driven pageant. Mark Bramble's book is a slim autobiography delivered by P.T. Barnum (Arie Gonzalez). It purports to show "the world's biggest humbug" as Barnum capitalizes on his grand vision of entertainment for the masses. It paints a picture of his devotion to his wife, Charity (Allison Appleby), hints at a liaison with Swedish opera star Jenny Lind (Nona Watson), and hopscotches through his "philosophical folderol" and political aspirations. After the death of his wife and a disappointing bid for election, he rejoins the world of the circus by collaborating with James A. Bailey (Jay A. Donnell) to form "the Greatest Show on Earth."

The four principals have fine voices, and their delivery of Cy Coleman's music and Michael Stewart's lyrics enhances the pleasant but unremarkable score. Gonzalez makes a rambunctious dreamer, and his energy ramps the show up a notch. The chemistry between Gonzalez and Appleby also adds texture.

The supporting players deserve kudos. There are jugglers, unicyclists, stilt walkers, trapeze artists, and gymnasts who provide a steady backdrop for Barnum as he takes his show on the road. Among those performing are members of the Great American Youth Circus, and they are terrific. Director Dan Regas and choreographer John 'Jahnathon' Whitfield keep the action brisk and varied as they move circus performers fluidly in and out of the central story line. Also notable is diminutive Jennifer Wilcove, first as a 160-year-old circus performer and then a blues singer in "Black and White." Her voice packs a punch.

Costumes by Diane Lewis, lights by Tim Swiss, sound design by Colin Trevor, and conductor Carmen Dominguez's music direction enliven Saddleback Civic Light Opera's first entry in its 30th anniversary season. What the play might lack in depth is made up for in youthful exuberance and animation.

Presented by Saddleback Civic Light Opera at the McKinney Theatre,

Saddleback College, 28000 Marguerite Parkway, Mission Viejo.

Fri. 8 p.m., Sat. 2 & 8 p.m., Sun. 2 p.m. Jun. 8-24.

(949) 582-4656.