Tempo; Restrictions; Design Recommendations - Motorola E398 User Manual

Sound

Tempo

The tempo of the base track must be specified at a time 0 of the base track file. Tempo is
specified in microseconds per quarter note in a standard MIDI "Set Tempo" meta-event. If
the tempo is not set in the MIDI file, or is not set at time 0, the tempo will default to
500,000 microseconds per quarter note (120 beats per minute). Tempo changes in the
middle of the base track file will be ignored.
The MotoMixer user interface provides the user with an option to adjust the tempo of the
base track. This user-specified tempo is saved as part of the mix file. The user is allowed
to adjust the tempo on a scale of 0-7. Setting 3 is the default value and will be equal to the
tempo specified in the base track file. Setting 0 is approximately equal to half of the
default temp. Setting 7 is more than double the default tempo.

Restrictions

The implementation of the MotoMixer feature uses a MIDI Text Event containing the text
"\!" (backslash exclamation mark) in the form:
FF 01 02 5C 21
Base tracks will not contain text events matching this format. Text events that contain
other text can be included at any point in the base track file.
In addition, files should be created to allow for a maximum polyphony of 16 simultaneous
notes when all tracks and effects are active.

Design Recommendations

Individual instruments' variations should be varied greatly to allow for an easily
discernable difference between variation 1 and 2. This can be accomplished by using
different rhythmic, harmonic, and melodic structures. One possible recommendation is to
use a more basic structure for variation 1 and a more complex one for variation two
(steady rhythm vs. syncopation). There must be an easily recognizable differentiation
between each of the variations.
With regards to variations with effect, these tracks can be used in a multitude of ways.
One possibility is to use the effect track to add harmony to a melody of an associated
track. Additionally, the effect track can be used to add musical substance such as
arpeggiations or figured basses. Lastly, the effect track can be used to add delay effects
such as echo by copying all musical events and pasting them at a short (1/32) offset.
Overall, the effect track should be used to add rhythmic, harmonic, or acoustical depth to
the associated variation track.
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