for performance purposes. MIDI controllers allowed one to split the keyboard into two or more sections and assign each section to a MIDI channel, to send note data to an external keyboard. Many consumer keyboards offer at least one split to separate bass or auto-accompaniment chording instruments from the melody instrument. Minikeys: Most electronic keyboards have keys that are similar to the size of keys on an acoustic piano. Some electronic keyboards have minikeys, either because they are targeted at child users or to make the instrument smaller and more portable. Accompaniment backing tracks: Pre-programmed musical accompaniment tracks (also called rhythm pattern or rhythm style by some manufacturers), consist of a variety of genres for the player to use (e.g., pop, rock, jazz, country, reggae). The keyboard plays a chord voicing and rhythm which is appropriate for the selected genre. In general, programmed backing tracks usually imitate the sound of a rhythm section or an ensemble. Certain keyboards may include a feature that allows the performer to create, compose and customize their own accompaniments. This feature is usually called a pattern sequencer, rhythm composer, or a style creator. In addition to the basic accompaniment tracks, some keyboards have an extra feature to play different loops in conjunction with the backing track itself. Accompaniment sections and synchronization: Usually, backing tracks comprises two to four sections, as well as fill-in patterns, introduction/ending patterns, and various synchronizations to improve the effects of the accompaniment. Tempo: A parameter that determines the speed of rhythms, chords and other auto-generated content on electronic keyboards. The unit of this parameter is beats per minute. Many keyboards feature audio or visual metronomes (using graphics on a portion of the display) to help players keep time. Auto harmonization: A feature of some keyboards that automatically adds secondary tones to a note based upon chords given by the accompaniment system, to make harmony easier for players who lack the ability to make complex chord changes with their left hand. Wheels and knobs: Used to add effects to a sound that are not present by default, such as vibrato, panning, tremolo, pitch bending, and so on. A common wheel on contemporary keyboards is the pitch bend, adjusting the pitch of a note usually in the range of ±1 tone. The pitch bend wheel is usually on the left of the keyboard and is a spring-loaded potentiometer. Drawbars: Usually found only on