Creating the
Outline |
Most music tunes have patterned structure.
For example, a rock tune has an introduction, several themes
(phrases of about two to four measures(bars)), and an ending.
As the
first step, the outline of the tune is created using random
numbers. In Automated Composing System, the parts of
outline is referred as pattern. Pattern is a chord
repetition pattern. A pattern can be considered as a theme. The length of
pattern is
determined by pattern length.
The Automated Composing System does not have an introduction
part. Therefore, the number of themes(patterns) and how many times
they are repeated have to be determined from random numbers.
The last theme(patterns) and the ending always have the same
structure.
For example, outline is like [theme-A]
[theme-A] [theme-B] [theme-B] [theme-B] [last-theme]
[ending]. The shortest outline is
[theme-A] [last-theme] [ending]. |
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Creating the
Chord Progression |
In this step, the chord progression of the
tune and length of each measure(bar) will be determined using the
outline.
This process is done by using random numbers and a
knowledge-base. The knowledge-base includes my way of
composing a lot. There are some other methods that do not
use knowledge-base.
In the Automated Composing System, chord progression is a
set of chord blocks. Every chord block has length and chord
name. Chord name determines what notes are included in the
chord block. If you want to see information about chords of
the Automated Composing System, click
here
The first chord of the tune must be CM7, Am7, C7. If the
major key is selected, the first chord is CM7, if the minor
key is selected, the first chord is Am7, and if the tune is
Blues, the first chord is C7. Chords after the first chord
are determined from the prior chord and a database. The
different chords are selected depending on the setting of
chord progression (Complexity of
Chord progression ) such as "complex" and "simple." |
For the
last theme (verse), a different database is used because it
needs resolution. The ending chord is always the same chord
as the first chord. To know about this, you might see
the operation of constructing knowledge base. Click
here.
The length of each chord block is determined using random
numbers, and they will be from one to eight times of quarter
note length.
For example, [CM7 of whole note length] [Em7 of whole note
length] [Am7 of half note length] [G7 of half note length]
are assigned to [theme-A]. |
If the Enable Transpose
is selected, some part of chord progression is transposed.
First, two location of where transpose begins and where
transpose ends are selected. Next, interval of transpose
will be selected from random number. At last, chords
of selected area will be transposed with selected interval. |
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Creating the
Harmony track and the Rhythm track |
In this step, the harmony and the rhythm
tracks are created using the determined chord progression.
The generation process of the Harmony track is very
complicated since each music style has a different pattern.
Although a typical pattern is prepared to use, rhythm and
notes are modified to avoid a monotonous sound. For example,
the Harmony track includes tension notes if it is for jazz
music.
The Rhythm track is very patterned. Although, it uses simple
patterns, it may contain fill-ins occasionally. |
User does not have control over fill-ins
although they might be rare. |
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Creating
Melody Tracks |
Melody tracks are also created based on
chord progression. In this process, the contents of the
Harmony track and the Rhythm track are not referred to.
This process is also done by using random values. However,
this time, random values are not used directly.
Each theme is processed at a time.
The Automated Composing System uses some
algorithms to
produce melody line. |
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Coordination
of tracks |
Finally, dissonant, such as minor 2nd and
major 2nd, between melody tracks and harmony tracks are
deleted. For some music style, such as Jazz, that allows
dissonant, this process may not be necessary. |
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