An expression pedal is a common control present on many different musical instruments, such as electronic keyboards, pianos and even popular pedal steel guitars. The player uses the expression pedal to manipulate various aspects of the musical sound, most commonly pitch. When using the expression pedal it is necessary to use some sort of chord/tone combination that is predetermined. This is done by plucking (oscillation) or vibrating (chords). In essence, this allows the player to create sounds that are beyond the normal boundaries of a regular note.
Expression pedals generally come in two forms, with one for the direct play of a chord and another for the indirect play of a chord/tone. They are often seen as a type of "stomp-pedal" as they are most often placed in the bass part of a sound system. However, many producers of electronic music have been known to place them in the primary processing section of their computer, as they can be a very useful addition to a multi-effects unit. Multi-effects units often contain expression pedals to allow the mixing and matching of sound effects.
One of the most common uses of an expression pedal is in the playing of "pipe organs". In these organs, the pipes are played by a single pipe organist (the leader) while the rest of the ensemble plays the pipes rhythmically. Usually, this instrument is played without any vocals. Because of the lack of vocal ability, many performers find it difficult to express themselves through this instrument.
Expression pedals are sometimes used as a way to change the midi values from one track to another. For example, if a band decides to mix a song from one track with another, they might opt to record the track and save it as a midi file. However, if this recording does not have the proper midi values for the song, a suitable midi file can be played from an expression pedal. Likewise, if a band wants to change the tempo from one track to another, they could record this track and save it as a midi file as well. Rather than opening up another program to manage these changes, the Expression Pedal simply alters the existing midi values within the effect unit.
An expression pedal may be used on audio-based instruments such as drums or keyboards. However, its most popular use is on VSTs (virtual synthesizers) and MPC ( Musical Software) programs. A virtual synthesizer is a type of software that allows a user to create audio programs out of complex digital signal processing units. VSTs or virtual synthesizers can be included with many programs, allowing the creation of entire musical pieces, demos and entire songs. A volume pedal is incorporated into this type of unit, which allows the user to alter the overall tone or type of sound produced from a specific application.
One other application of an expression pedal that we are going to discuss today is the "squeeze" effect. The expression unit has a built-in oscilloscope which uses a mathematical algorithm to generate various waveform patterns. These patterns are then combined with VSTs, digital audio workstations and other recording programs to produce a wide range of different sounds. A squeeze oscillator is used in conjunction with the expression unit to produce different levels of vibrato. For instance, a simple squeeze signal created using a VST with the Expression pedal and an audio source would produce a subtle, percussive waveform. In this example the octave range of this sound could be anything from a single note up to a complete chord progression.
An important function of the Expression Pedal is the ability to introduce other controls such as volume, pitch bend and sustain through the midi device. This is accomplished by a combination of two functions: the first being the "on" switch which enables the foot pedal to operate independently of the main unit, and the second being the "volume" function which adjusts the overall volume of the midi device. The unit is also equipped with an external control section which can be used to control such things as the "tone", "strength", "pitch bend" and " sustain only". Additionally, some Expression pedals have a USB connectable port which enables any computer to be connected to it and enables the user to transfer its files directly to a normal computer hard drive or other midi device.
Using an expression pedal can be incredibly useful for a wide variety of purposes including creating music production, MIDI sequencing, live performance and much more. However, if an Expression Pedal fails or malfunctions it is important to ensure that an immediate repair is carried out. If the foot pedal does not function properly an owner should first power the device down and then connect a USB cord to the computer using a standard USB cable. The owner then needs to make sure that the device's battery is fully charged. If these measures are taken there is a good chance that the device will continue to work well for many months to come.