Apple Logic Pro 9 - Manual (Page 856)

The Change Display Only mode does not work with Apple Loops used on audio tracks.
This shouldn’t pose a problem, as you won’t normally need this function when working
with Apple Loops. There is one exception, however: some Apple Loops contain chord
progressions. These chord progressions are not displayed in the Chord track. Unfortunately,
you can’t use the Chord track’s Change Display Only mode to match the displayed chords
to what is actually being heard. All changes in the Chord track affect the transposition of
(audio, not instrument) Apple Loops. Activating the Change Display Only option doesn’t
help.
To work around this problem
1 Cut the (audio) Apple Loops file at the precise positions of any chord changes.
2 Match the chords displayed in the Chord Track with the chord progression in the cut
Apple Loops files by manually entering the chords of each section in the Chord track. The
individual Apple Loops parts will then be transposed accordingly.
3 Enter the inverted Transposition values of the chord root note changes in the Region
Parameter box of each section, so that playback of the Apple Loops parts will match the
original Apple Loops file.
For example, assuming a default project key of C:
• The (audio) Apple Loops file contains a chord progression with root notes of C, F, G,
and C. Cut it at these chord change positions. This will result in four regions.
• Enter C, F, G, and C at the corresponding positions in the Chord track. Assuming the
original key is C, this is equivalent to a transposition of the second region by +5 and
the third region by +7 semitones. If you played the entire part at this point, the original
audio material would be transposed by the amounts just entered in the Chord track,
which isn’t what you want.
• Set the Transposition value of the second region to −5, and of the third region to −7
in their respective Region Parameter boxes.
Playback of the whole part will now sound as it did before the cuts, and the correct chords
are displayed in the Chord track.
Using the Transposition Track with Apple Loops
Transposition events are closely linked to the progression of the chord root notes in the
Chord track: Changing a chord root will be reflected in the Transposition track, and vice
versa. Any alteration or creation of a transposition event will generate or alter the
corresponding chord in the Chord track. All Apple Loops and MIDI regions will be
pitch-shifted accordingly.
Note: Standard audio regions (audio regions that are not Apple Loops) will not be affected.
Nor will Apple Loops that do not have a Key definition (drum loops, for example).
856 Chapter 30 Creating Apple Loops