of Microprocessors

CONTROL SEQUENCE DISPLAY AND EDITING 363
P04
P03
P02
POI
P3
•
P2 • •
PI
•
•
• • •
•
VI
V2
C4 E 0 CEO G
G2
A
C
B
V3
GI
E
G
Fig. 11-10. Typical display of portion of rhythm sequence
display screen. Each line of symbols represents a different percussion instrument.
For those with initiation points only, a simple point is plotted when
the sound starts. For those with duration, a line connecting initiation and
conclusion points is drawn. In the general case, percussion sounds are combined
with notes of a definite pitch, which themselves have a duration and
can be represented by lines as well but with an identifier, perhaps a small
letter or number over the line, to specify the note's pitch, amplitude, or
other information. Parameter curves for complex sounds could be mixed in as
well.
Editing functions for on-off controls are much simpler than for parameter
curves, since time is the only significant variable. Essentially, all that can
be done is to move initiation and conclusion points forward and back, delete
events, and add events. In the case of identified events, the identification can
be changed. It would also be desirable to be able to reassign a string of events
to a different instrument.
Note that all of this is starting to approach a method of computer music
notation but with a heavy graphic orientation. Actually, standard music
notation is somewhat graphic, at least in the representation of note pitches
and to some extent note sequencing, but beyond that it is strictly symbolic.
A system could certainly be set up to conveniently enter and edit music