How The Number Of Simultaneous Notes And Voices Are Related; Legato-Enabled Sounds - Roland SC-8820 Owner's Manual

Parts and Sounds

Legato-enabled Sounds

The SC-8820 provides legato-enabled sounds, which are ideally suited to legato
playing, and can realistically simulate this instrumental performance technique.
To understand this feature, consider how most string instruments produce sound.
Usually, a brief attack-like sound will be heard only at the very instant the string is
made to vibrate. After that a much mellower, attack-free sound continues to emanate
during the string's vibration. The legato-enabled sounds simulate such variable at-
tack-portion characteristics of string sounds by switching on or off certain special
voices within an Instrument according to the way the keyboard is played.
Try out one of these sounds to hear how it works. Play a note and keep your finger
on that key while playing another note. You should hear a distinct attack portion
with the first note you play, while the second one contains almost no attack compo-
nents, and sounds much smoother.
fig.4-21
If you want to sound the attack portion each time, simply release your finger from a
key before playing the next note.
fig.4-22
How the Number of Simultaneous Notes
and Voices Are Related
On the SC-8820, the sounds are made up of voices, the smallest unit of sound gen-
eration. There is a limit to how many of these Voices can sound at once, and in the
case of the SC-8820, up to 64 simultaneous voices can be used. Some sounds (Instru-
ments) use 1 voice and others use more (Instrument List, p.107). The main reason for
using more than 2 voices is to allow different timbres to be produced by different ve-
locity values, or to produce richer textures by layering the multiple sounds.
If more than 64 voices are used at once, later-sounded notes will be given priority,
and notes sounded previously will be turned off, starting from the oldest. If you use
only single-voice Instruments, you will be able to play 64 notes simultaneously, but
if some of the Instruments are more than 2-voice ones, you won't be able to play 64
simultaneous notes. Even if a MIDI Note Off message (p.99) is received, voices will
be used for as long as the sound is heard. Be aware of this especially in the case of
sound with a long release (p.35).
26
Legato control cannot be
switched on and off on an
Instrument basis. You
should choose and edit an
Instrument that meets your
intended usage.
If song data created with 64
voice playback in mind is
played back on a sound
generator with fewer
voices, some notes will
drop out, and the musical
result will not be as it
should. The SC-8820, the
SC-88Pro and SC-88 has 64
voices, the SC-55 has 24
voices, and the SC-55mkII
has 28 voices.