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Quantize engine – Apple Logic Pro 7 User Manual

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416

Chapter 11

Sample Editor

A Score window, containing the transcription of the audio file generated by the
function, opens automatically. The Score Editor uses a score style called Audio To Score
with three staves. This style can be edited just like a normal score style. The three staves
contain the following information:

Stave 1 contains the pitches that were most clearly recognizable. All of these notes are
assigned to MIDI channel 1.

Stave 2 contains the pitches that were less clear—if the pitch is wrong, or could not be
clearly identified by the first analysis. These notes are assigned to MIDI channel 2.

Stave 3 contains all other information provided by the function, on MIDI channel 3. As
an example, detuned pitches produce a “dummy” note (C3 on MIDI channel 3). This can
happen if the trigger point has a very short attack, or if the note has a high interference
element (such as click noises or buzzing guitar strings).

Depending on the selected file, notes can be detected more or less reliably. If the
detection is certain, MIDI notes are assigned to MIDI channel 1. If not, they are assigned
to C3 on MIDI channel 2, so that at least the starting point and length information can
be retrieved. The threshold for “certain identification” is defined by the quality
parameter. Logic also offers the option to define pauses as notes. This is especially
useful for MIDI Groove templates, and ensures that they don’t contain gaps. These gap-
filling notes appear as C3 on MIDI channel 3. They represent breaks, rather than sound
events.

A few tips on getting the best results from the Audio to Score function:

You will only get good results with clearly identifiable, monophonic audio material.
Solo voices, strings, and piano can be easily analyzed, as can any recordings with
distinct pitches.

Experiment with different parameter settings for data processing. Be prepared to
make several attempts, to determine the optimum settings for a particular recording.

Quantize Engine

This function allows you to use a MIDI Region template (within reason), to quantize an
audio recording.

This is done by using a dynamic time compression/expansion algorithm. The function
is similar to the Groove Machine, except that the quantize template can reflect values
other than just 8th or 16th note swing grooves. Even user-defined MIDI grooves can be
used.

The Quantize Engine is the reverse of the Audio to MIDI Groove Template function.