User`s guide

Pro Tools Reference Guide230
Default Tempo
New sessions open with a default tempo of
120 BPM. This tempo can be changed by
inserting a tempo event at 1|1|000. How-
ever, this is not the same as inserting nor-
mal tempo events at other locations. The
tempo event that resides at 1|1|000 is actu-
ally a Bar|Beat Marker (notice that it has a
blue triangle).
The main distinction is that this Bar|Beat
Marker can be dragged to any location
within the session (such as to align with a
particular SMPTE frame) to redefine where
1|1|000 is. This, in effect, moves everything
else in the session along with it. Any new
bars that precede the default tempo event
are numbered as negative.
Identify Beat Command
Bar|Beat Markers
The Identify Beat command lets you estab-
lish a tempo/meter map for audio that was
recorded without listening to the click, or
for imported audio with unknown tempos.
The Identify Beat command analyzes a se-
lection range (usually with a distinct num-
ber of beats or measures) and calculates its
tempo based on the specified meter. In do-
ing this, Bar|Beat Markers for the calculated
tempo are inserted and appear in the
Tempo Ruler at the beginning and end of
the selection; in addition, meter events are
inserted into the Meter Ruler.
Bar|Beat Markers look similar to tempo
events, but instead have small blue trian-
gles to indicate their location.
The key to accurately defining tempos for a
range of audio with the Identify Beat com-
mand is to make sure that the initial selec-
tion represents an accurate length of beats
or measures. In fact, you may want to first
loop the selection on playback (see “Loop-
ing Playback” on page 171) to see if it plays
cleanly without skipping. To avoid drift, se-
lect the audio material with the Time Scale
set to Samples rather than Bars:Beats.
▲ Tempo events and Bar|Beat Markers cannot
be mixed. If a session contains tempo events
and you attempt to insert Bar|Beat Markers,
existing tempo events are converted to
Bar|Beat Markers (and vice versa).
To add Bar|Beat Markers for a one-bar drum
loop:
1 Place a one-bar drum loop at the begin-
ning of an audio track.
2 Select Display > Samples. This ensures
that the selected audio material will be
sample-accurate.
3 Select the audio region with the Grabber
and choose Edit > Identify Beat.
Bar|Beat Marker