Pro Tools 101_ An Introduction to Pro Tools 11 ( PDFDrive )

the audio clips’ positions relative to the session’s bars and beats will
change.
Audio tracks can also be set to tick-based operation to perform specialized
functions, such as tempo matching for Elastic Audio. For the purposes of this
course, whenever we discuss recording and editing audio, we will assume
sample-based operation unless otherwise stated.
Tick-Based Operation
In tick-based operation, recorded information is tied to specific Bar|Beat
locations in an arrangement. When you record MIDI data, Pro Tools uses
tick-based timing to determine the locations of your MIDI events. MIDI
events are recorded relative to particular bar and beat locations (such as Bar
16, Beat 1), and their absolute locations adjust based on the session tempo—
if the tempo increases, the MIDI data will play back faster, and individual
events will occur earlier in time; if the tempo decreases, the MIDI data will
play back more slowly, and the same events will occur later in time.
Note: The Elastic Audio capabilities in Pro Tools enable the same
functionality for audio on tick-based tracks, allowing audio clips to
automatically compress or expand to conform to the session tempo.
Pro Tools subdivides the bars and beats in your session into ticks, with 960
ticks comprising a quarter note. Timing can thus be specified with a
precision (or resolution) of up to 1/960th of a quarter note when measuring in
bars and beats. You can think of tick-based locations as relative locations in
time, measured by the number of bars, beats, and ticks that have elapsed
since the beginning of the session. A tick-based event maintains its rhythmic
location relative to other tick-based events in the song, regardless of the
session tempo—but a tempo change will cause the event to occur earlier or
later in absolute time, thereby changing its location relative to any samplebased
audio in the session.
Tick-based tracks and data coexist with sample-based tracks and data within
the same Pro Tools session.
Tip: Pro Tools displays relationships between audio and MIDI
accurately in the Edit window at all zoom levels, with MIDI event
durations drawn proportionally to the Timeline, according to tempo.