Auto accompaniment

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An automatic accompaniment , also called an automatic accompaniment or arranger in English , is often part of a keyboard . The auto accompaniment can be viewed as an accompaniment band. The player selects an accompanying rhythm from a variety of rhythms and accompanies himself with drums , bass and other accompanying instruments.

Playing with the Auto Accompaniment

For playing with the automatic accompaniment, the keyboard is divided into accompaniment and melody. The musician plays the melody with his right hand and the chords of harmony with his left hand . The left hand does not play a rhythm, but leaves the chords or only plays them briefly. The chord determines the harmony of the accompaniment until a new chord is played. Many automatic accompaniments offer a one-finger automatic in which one or two keys define a chord.

In addition, the player can change the rhythm using additional control elements on the keyboard and otherwise control his accompaniment in a variety of ways.

Structure of the accompanying rhythms

Each rhythm consists of several instruments. The bars of the instruments are divided into sections such as Intro, Main, Fill In, Ending, etc. These sections, so-called sections, are called up directly on the keyboard via buttons when playing. They usually consist of a relatively small number of bars. In addition, there are different variations per section, such as Intro A, Intro B, Intro C or Main A, Main B etc. The automatic accompaniment is often started with an intro, which then merges into a main section. A characteristic of the main sections is that at the end they are played over and over again until the player selects a new section. If AutoFill is switched on, when changing to a new main variation, a suitable fill-in is automatically inserted before the requested main variation is played.

Each instrument has a separate accompaniment pattern for each variation of a section, a so-called pattern. These patterns consist of notes that were played in a certain chord, the so-called source chord. In addition to the note section, there are a number of so-called transposition settings for each individual pattern, which are also saved with the source chord.

The combination of the different patterns with their sections and variations to form an accompanying rhythm is called a style. The internal structure of the styles is relatively complex and depends on the respective keyboard manufacturer.


A chord recognition identifies the underlying chord from the notes played by the left hand, whereby inversions can also be resolved. Whenever the player picks up a new chord, the accompaniment is immediately recalculated and played with this new chord. The recalculation of the accompanying rhythm is achieved with so-called transpositions, which, with one exception, are not transpositions in the musical sense. These transpositions are done in real time . The automatic accompaniment is therefore a real-time system with correspondingly high hardware and software requirements.

With the transpositions, the notes of the pattern are converted into the played chord type. Since the chord type of the pattern is defined, z. B. the notes that represent the third in the pattern are known. When you play a major chord, these notes are converted into a major third, and when you play a minor chord, they are converted into a minor third. The same procedure is used for the other chord intervals. This is the basic technique with which patterns are converted into the different types of chords. In addition, the new pitch is calculated from the position of the root of the played target chord in relation to the root of the source chord.

With the root note of the target chord played, the pitch of the accompaniment can shift in a range of 11 semitone steps, i.e. by almost an octave, during transposition. This large change in pitch is not acceptable in many cases. For this reason, the Auto Accompaniment has additional parameters that limit the changes in pitch of the accompanying instruments while playing.

One method is to start from a certain root note of the chord being played (so-called high key), e.g. B. from G to transpose the accompaniment down instead of up. The individual chord tones keep their original interval position .

Another method abandons the interval position of the individual chord tones and uses inversions with the shortest possible transitions of the individual tones for the chord change . The tone of the third of the previously played chord can then, for example, become the root of the next chord. The accompaniment approaches playing like you know it from a guitar.

Again, these measures are impractical for patterns with melodic lines because they lead to caesuras in the course of the tone. That is why there are special transpositions for these cases as well. Overall, a large number of very different transposition methods with corresponding parameters are used.

Advantages and disadvantages

Since multiple instruments are played at the same time, the auto accompaniment creates a richness of sound that a player alone could not achieve. In addition, the automatic accompaniment helps beginners to learn an instrument, since audible successes can be achieved relatively quickly.

The automatic accompaniment offers the experienced musician many design options to play their own arrangements and to vary them spontaneously. He has an unmanageable abundance of accompanying rhythms for almost every genre of music.

What sets the automatic accompaniment apart is the fact that the rhythms can be freely transposed. A title can be played with different rhythms. The automatic accompaniment opens up the playful handling of rhythms and harmonies.

However, these advantages come with a disadvantage. Playing the patterns with different chords is possible because the accompaniments are primarily reduced to chord tones. In fact, however, additional notes can be played for each chord, which result from its chord scale. Since these notes are not played, the automatic accompaniment limits the musically available notes of the accompaniment. The enrichment of individual, mostly short tones such as B. with cha-cha-cha and bluesy styles like R&B nothing.

To get around this limitation, patterns are used that contain their own melodic and harmonic components and in this way expand the sound supply. Playing these patterns is more or less like a playback , because the assigned transpositions evaluate either none or only one or two notes of the played chords, while they play the other notes themselves.

There are therefore also other systems that use the available notes of the accompaniment when playing by transposing the chord scales. However, this assumes that the musical context of the chords played is included.


Most of the accompaniment machines should be installed as an integral part of an arranger keyboard. There are also dedicated hardware solutions with their own housing and software implementations that are operated on a PC. Due to their compactness, the keyboards are easier to use and more suitable for the stage. In contrast, software solutions can be configured flexibly, as they are independent of the keyboard and sound module. They usually offer additional unique selling points.


  • Reinhold Pöhnl: Styles & Patterns of Musical Playing with the Yamaha Accompaniment , 3rd Edition 2010, PPVMEDIEN GmbH, Bergkirchen 2003, ISBN 978-3-941531-49-9 .
  • Barrie Nettles Richard Graf: The chord scales theory & jazz harmonics , advance music GmbH, Mainz, ADV 11215, ISBN 978-3-89221-055-9 , ISMN 979-0-2063-0298-5.

Individual evidence

  1. Reinhold Pöhnl: Styles & Patterns of Musical Play with the Yamaha Accompaniment , 3rd edition 2010, PPVMEDIEN GmbH, Bergkirchen 2003, ISBN 978-3-941531-49-9 , pages 73-92