This episode is certainly not the greatest episode of "I Love Lucy" that was ever aired. Nowadays, we are used to epic drama and gore (Cp. Grey's Anatomy and Spartacus and True Blood), but watching this episode takes the viewer back to a time where TV was innocent, fun, and relied on the immense skill of the actors.
Ricky is a bandleader (again, something relevant to the time period for which there is no equivalent in 2011) and Lucy, his wife, gets the idea in her head that she would love to be involved with his show. When one of the acts (Pepito) in Ricky's show is unable to perform, Lucy surprises everyone by showing up in a guise similar to Pepito's.
The interactions between Ricky and Lucy when she first shows up on stage at Ricky's show are absolutely priceless. They should definitely have you laughing aloud. The segment from "I need to see your credentials" onward is top-notch humor! I absolutely love Lucy's facial expressions - she truly makes the show. The viewer is also treated to a singing number by Ricky "Cuban Cabbie" about a cabdriver in Havana who disdains the use of a motor vehicle in favor of a horse and buggy.