For clarification, the pedal tone that wikipedia informed you of is not the pedal tone you want. You are looking at a pedal point, which, as other posters have informed you of, is a sustained tone over which other chords are played. In a typical sonata form, a pedal tone is used to establish te dominant triad just prior to the recapitulation. It is used to build suspense and tension.
The pedal tone that wikipedia mentioned is a set of very low tones on a brass instrument. Now, I play tuba, so naturally, I know all about these. My tuba is a CC contrabass tuba, meaning that the fundamental pitch is a C, the fourth note on an 88-key piano. It is commonly referred to as pedal C. There are a set of notes around that note which are called pedal tones. I went to a tuba convention recently in which I played an F bass tuba, for which the fundamental is the fourth ledger line F below the bass clef staff. This pitch vibrates at somewhere in the 40-50 hz range. However, I managed to play lower than that, a phenomenon which I believe woodwinds refer to as undertones. I actually achieved a double pedal F, the space below the seventh ledger line below the bass clef staff, which vibrates at about 22 hz, and is a half step higher than the lowest pitch audible to humans as a pitch rather than individual beats. I also played every note chromatically between the two pitches, and I beat out the contrabassoon as the lowest pitched instrument. Anyway, I digress. A brass pedal tone simply refers to the fundamental pitch of the instrument and the lowest tones surrounding it.
