The Sketch Format
Sketch writing allows you freedoms you don't get with a longer format such as a play, sitcom, or screenplay. It allows you to explore ideas and develop characters in a very efficient way. You can explore a single idea or premise for a sketch. A sketch can be an excuse for showcasing an interesting character. You try the joke in front of the audience and see if it works, And you can immediately integrate any changes into the next show.
Many comedy theater troupes such as Second City, the Groundlings, the Upright Citizens Brigade, Improv Asylum, and local groups in your area offer classes in improvisation and sketch. Class members have even been known to become full-fledged members of the troupe. Look for classes in your area and take the plunge into the world of improv and sketch comedy.
With a movie, you have at least ninety minutes to tell your story. With a sitcom you have around twenty-two minutes. With a sketch you have a fraction of that time, but you still need to introduce the characters, set up the joke, and have a beginning, middle, and end. It's a hit-and-run, guerilla-style form of comedy, and that's what makes it satisfying to an audience.
You need to work fast; sketches longer than ten minutes can start to drag. You need to get to the joke in the most efficient way you can. Don't be afraid to write a sketch that is thirty seconds long; it can be followed by a seven-minute sketch without a problem. But, don't make every sketch seven or eight minutes long. Variety in the material is what makes for a successful sketch show, so sketches in the same show can go from subtle to outrageous.
Every sketch, with time, can have a great, logical ending. However, when you are short on time, such as on a weekly television show, a sketch can start out with a great idea and end without a logical conclusion. It's presented as sort of a slice of life that just fades out to commercial. On TV you only have one chance to get it right, but on stage you can change a sketch until it works. A sketch can start out as one thing and morph into something completely different over time.
Production constraints are another problem with television sketch comedy. The more elaborate the set and scenery, the longer the sketch is going to be, whether the concept of the sketch can handle that time or not. It comes down to expense; if the set costs a lot, the producers want to get their money's worth, sometimes at the expense of the sketch. If there is last minute inspiration for a great joke that requires a set change, chances are you'll have to leave the sketch the way it was.
You can find the entire history of sketch comedy on DVD. Check out Your Show of Shows, The Carol Burnett Show, Saturday Night Live, SCTV, MADtv, Kids in the Hall, Mr. Show, Chappelle's Show, and The Ben Stiller Show. You need to know where comedy's been before you can see where it's going. Expose yourself to as much good sketch comedy as you can!
With stage sketches, the audience will suspend their disbelief and accept sets that merely suggest the situation. A simple table can be a desk, a dinner table, or a service counter in a fast food restaurant. Sometimes the lack of a budget for costumes and sets means more satisfying comedy with stronger endings. Elaborate sets, props, and costumes can distract the audience from the essence of the joke.