ENSONIQ EPS-16 PLUS, Руководство музыканта

Страница: 179 / 260

EPS-16 PLUS Musician's Manual
Section 8 — Sequencer Basics
Digital Sequencing
Now imagine a recorder which, instead of recording the sounds of an instrument,
records the same kind of digital information that is sent and received over MIDI
— key down, key up, key number and velocity, pitch bend, mod wheel, program
changes and so on — and you have imagined a digital sequencer.
A sequencer records and plays back the "control information" rather than the
actual notes. This means that there is no degradation of the sound in the
recording process no matter how many times you overdub or re-record a part. A
sequencer is sort of like an electronic player piano.
It is important to bear in mind that a sequencer only records what you play.
Sequencer memory is used up on the basis of Events (keys struck, controllers,
etc.), while a tape recorder's memory (the tape) is always used up by the same
amount over a fixed period of time.
This means that a sequencer will use virtually the same amount of memory to
record 100 notes, whether you play those notes over ten seconds or ten minutes.
When you strike a key, the sequencer records a Key Down event. It then counts
the clock pulses until you release the key, when it records a Key Up event The
amount of time between the key down and the key up doesn't really affect the
amount of memory required to record the note. Compare this to an audio tape
recorder. With tape, time is the main factor. A tape recorder will use the same
amount of tape to record a minute of music, whether the signal contains one note
or one hundred.
You might say that tape is linear — it is spent at a fixed rate — while digital
sequencer memory is dynamic — it is used only as needed Understanding the
difference will help you to manage the EPS-16 PLUS sequencer memory. For
. example, while key events (the notes you play) use up relatively little memory
each, controllers such as pressure, mod wheel, pitch bend, etc., are recorded as a
flood of numbers which can fill up the memory in a hurry. Thus if you're trying
to squeeze one more track into a sequence when there is not much memory left,
you should go easy on the controllers.
What is a Sequence?
A sequence on the EPS-16 PLUS is a collection of eight independent tracks and
their associated notes, controllers, etc.
The EPS-16 PLUS can have up to 80 sequences in its internal memory at once.
Each sequence has a 12-character name, which you give to it when you create it.
A sequence can be up to 999 bars long.
You select the current sequence (which sequence you want to play or record) on
the EDIT/Seq•Song page. Press Edit, then double-click on Seq•Song to go
directly to the Select Seq/Song page.
You can save an individual sequence to disk, though in most cases it is more
useful to save the entire song with all its related sequences.
Sequencer Basics
8 - 3