Since the development of sliced bread, three innovations have been regarded as the greatest inventions of our era: Expo markers, Febreze, and mockumentaries.

Mockumentaries are satirical “mock documentaries” that play off stylistic elements of documentaries in a fictional context. Sources credit a short April Fool’s piece called “Swiss Spaghetti Harvest” as the first mockumentary. Woody Allen was a pioneer as well, exploring the form with such features as “Take the Money and Run” and “Sweet and Lowdown.” Of course, Christopher Guest is renowned as the master of mockumentaries. Interestingly enough, the mockumentary is one of the types of cinema that has been perfected and defined by both American and British filmmakers.

One popular route filmmakers have taken is combining rockumentaries with mockumentaries. This subgenre began with such films as “The Rutles” and “This Is Spinal Tap.” Much of the dialogue is improvised, a key reason for the characteristically quick and natural charm of these movies; yet the dialogue in musical mockumentaries only functions to build up to the climactic point and most anticipated parts of the movies, which are the songs. Musical mockumentaries typically have a repertoire of whole or partial parody songs that mimic (usually in a deadpan or otherwise serious manner) typical conventions of the musical genre they are spoofing. In Christopher Guest’s “A Mighty Wind,” three groups of folk singers pull from all the classic ingredients of folk music to create over a dozen fake folk songs. What makes these songs humorous is not usually the lyrics but the mannerisms of the performers and the perfection with which they have written carbon copies of so many familiar old folk songs. The more little tics the song has that echo the real songs of the genre the better. The lyrics are funny in how over-the-top they are, but they are not so outrageous as to take away from the deadpan feel of the film, so audiences are in a certain respect able to take them seriously as legit pieces of music.

This is not the case with all rock mockumentaries though. In films such as “CB4” and semi-mockumentary “Walk Hard,” the lyrics have an equally important function as the style of the songs. The result is that the humor is more obvious (though there is still much subtlety in form as well), making the film more laugh-out-loud funny. These films rely a little more on jokes than satire, though satire still drives each film as a whole.