10.6

717Logic Pro Instruments
• Frequency/Rate: Determines the speed of the waveform cycles produced by the LFO.
When it is set to low values, very slow ramps are produced, making it easy to create
sounds such as ocean waves rolling in—when white noise is chosen as the waveform in
the main oscillator.
• Sync mode: Allows you to choose between free running—a user-defined LFO rate—or
synchronization with the Logic Pro project tempo.
• LFO Envelopes: The LFO can also be controlled with an envelope generator in some
synthesizers. For example, imagine a sustained string section sound where vibrato is
introduced a second or two into the sustained portion of the sound. If this can happen
automatically, it allows you to keep both hands on the keyboard. Some synthesizers
include a simple LFO envelope generator for this purpose. Often, this envelope consists
only of an attack parameter—some may also include decay or release options. These
parameters perform in the same way as the amplitude envelope parameters (see Attack,
decay, sustain, and release), but they are limited to control of LFO modulations.
Global controls
Global controls affect the overall output signal of your synthesizer.
Common global controls
• Level or Volume: Sets the overall loudness of your sound. This control is the master
output volume control of your synthesizer.
• Tune: Sets the overall pitch of your sound—typically in semitone steps. Many Logic Pro
instruments provide additional fine-tuning in cents; a hundredth of a semitone.
• Glide (portamento): Sets the amount of time that it takes for one note pitch to slide up
or down to another note pitch. This control is useful for emulating wind instruments that
slide from note to note, rather than move directly to another clear and distinct pitch.
• Bender/bend range: Bends the pitch—the oscillator frequency—up or down. This control
is generally hard-wired to a pitch bend wheel on a keyboard. As the name suggests,
moving the wheel up or down from its centered position bends the pitch up or down.
The Bender/Bend Range parameter usually has an upper and lower limit of one octave
but is typically set to around three semitones up or down. This setting is ideal for
emulating small (or extreme) pitch fluctuations that occur in some instruments—such as
when moving between notes with a trumpet, or bending the strings during a guitar solo.
• Voices: Sets an upper limit to the number of notes that can be played at a given time.
Producing notes simultaneously is known as the polyphony—literally, “many voices”—of
the instrument. The Voices parameter sets an upper limit to the number of notes that
can be produced simultaneously.
• Unison: Used to “stack” voices—with the unison voice being heard one octave above
the frequency of the played note. Because two voices are being used when you play
a note, unison has two effects—it makes the sound richer and fuller, and it halves the
polyphony.