Song parody is a form of musical comedy in which the performer mimics certain aspects of already-existing material as closely as possible, while placing it in a new, ridiculous context. Most commonly, song parodies feature silly rewritten lyrics, which are usually based on the sound patterns of the original words and performed to the original music -- the closer the resemblance, the more clever the parody, although ideally, the new lyrics are wacky enough to stand on their own as well. Some song parodies also add humorous instrumentation or sound effects, while others rely as much on the silliness of the new context as the skill with which they ape the original. Sometimes, parodies don't rewrite a specific work, but rather exaggerate the mannerisms of a certain style or artist in new (yet similar) compositions -- it's up to the audience to make the connections and catch the references. However, even though the frame of reference is larger, the key elements of parody -- mimicry and comic recontextualization -- are still present, and a full understanding of the humor still depends upon recognition of the source material. Since humorous exaggeration is so important to this style of parody, it's the one that most frequently crosses the line into satire -- i.e., making specific, pointed commentary on the performers, fans, aesthetics, or other qualities associated with the original works. Whatever their scope or ambition, though, song parodies have long been the most popular type of musical humor, simply because anyone can at least try their hand at the form.