"Improvising for the sake of improvising usually leads to banalities or irrelevant jokes." -- Gene Wilder

I saw a recreation of a radio play featuring an actor playing Groucho Marx. Near the beginning he improvised something related to the script which got a great laugh from the audience. A little later something went wrong, and he improvised a response that got another great laugh. During the second half of the play he began improvising just because he thought people were responding well to his improvisations. Now his comments were not related to the story. He began making comments about other subjects if he thought they might get a laugh. His comments did not get the response they had originally because they were irrelevant and not set up well. Instead of returning to the script and trusting the material, he panicked and began doing more improvisation. He began ad libbing comments about the inadequacy of the script, although he was ignoring it. When his ad libs did not get laughter he began using face savers like repeating something that had gotten a laugh earlier in the show. Only three people laughed at one of his comments, and he turned to them and thanked them for saving him. The other performers had trouble moving the show along. They failed to get laughs for jokes that were scripted in their lines because he kept interrupting them. In his desperate attempt to get laughter by improvising he ruined the play because he was no longer paying attention to it. At one point he had to return to the script, but had no idea where they were. One of the other actors had to turn to the correct page for him and point out his next line. His selfishness prevented the others from doing a good performance. It also had a negative impact on the audience because his ad libs made the play run over. That meant the audience had a shortened break before the next play would begin, and the performers in the next play had to rush to prepare their show.

By contrast I have heard many people comment on Jack Benny's generosity. Jack didn't care who got laughs during his performances as long as people remembered laughing during the show. Jack did improvise, especially when one of his cast members made a mistake. However, his ad libs were always in response to something that had happened during the performance. Part of his stage character was a supposed inability to improvise. He used that to point out the improvisational abilities of others he performed with. For example, when he was a guest on Bob Hope's TV program, Bob improvised a comment about Jack. Jack's improvised reply was, "You wouldn't dare say that if my writers were here."

Improvisation does play a role in a performance. It can make the characters seem alive by responding to something that has happened. If the audience can see and hear something, the entertainer should also see and hear it, and then respond. For example, I saw a performance of the live "Aladdin" show at Disney's California Adventure in Southern California. When a baby started crying in the audience, the actor playing the Genie turned to Jaffar, the villain, and said, "You should be ashamed of yourself."  

Improvisation can keep a show fresh and interesting for the performers and contribute to a sense of the performance happening for the first time. The Genie in the live "Aladdin" show is given license to improvise. People return specifically to see what new lines the Genie will add. However, the Genie's ad libs are controlled. After making a joke, often including a topical reference, the Genie returns to the script.

Ideally an ad lib helps to move the production along instead of bringing it to a halt. It adds to, instead of detracting from, the entire show. It must relate either to what is happening in the action of the script or to what is happening in the environment of the theater. Other than causing them to laugh appropriately at the humor in the improvised bit, it should not interfere with the ability of others to give their best performance.

 Why do you improvise in a show? What is the purpose of the improvisation? How can your improvisations contribute to the overall effectiveness of the performance? How can you make sure your ad libs are relevant?