The official soundtrack for Final Fantasy VII contains eighty-five unique tracks. In the game itself, the soundtrack consists of ninety-four separate MIDI files, including shortened and/or broken-apart versions of pieces such as "Those Chosen By the Planet", "Victory!", and "The Mako Cannon is Fired ~ Shinra Explodes". What very few people know is that within these ninety-four MIDI files is one that is never once heard in the game itself, which can be found by using Ficedula's utility Cosmo. You can download this track, whose file name is simply "COMICAL.mid", here.
Of course, the obvious questions are, "Why can't this track be heard in the game?" and "What was this piece intended for?"
The first question is a bit easier to answer. Like many of the "mysteries" that can be found in FFVII's programming, this MIDI is most likely an artifact from the game's production. Of course, the piece was meant to be left out of the finished game, but it seems as if Square's programmers left it in, probably by accident.
As for the intended purpose of this track, I noticed that it sounded similar to "Descendant of Shinobi" and "Materia Mountain". These two pieces are strongly associated with Yuffie, and can be heard during scenes where she plays a major role. Perhaps "COMICAL.mid" was meant for a scene with Yuffie that was later scrapped?
A second possibility is that this piece is meant to be included in a humorous scene, with or without Yuffie. The name of the MIDI file, as well as the lighthearted tone, lend itself to this possibility.