An octave pedal shifts the pitch of the guitar signal up or down by one or more octaves, adding depth, thickness, or a synth-like quality to the sound. Some pedals generate a sub-octave for a deep, bass-like effect, while others create upper octaves for a sharp, organ-like tone. Many modern octave pedals allow multiple octave layers and polyphonic tracking, enabling chords as well as single-note riffs. Octave effects are popular in genres ranging from rock and blues to funk and experimental music. Well-known octave pedals include the Boss OC-5, Electro-Harmonix POG series, and MXR Blue Box, offering a range of classic and modern octave-shifting tones.