Logic Pro X - Video Tutorial 21 - Tempo Changes with Flex Time Video Lecture | Logic Pro X: A Practical Hands-on Course - Music

hello this is music tech help guy
welcome to episode 21 of my Logic Pro 10
video tutorial series in this video
we'll talk about using flex time and
tempo changes in the previous three
videos we talked about how we can alter
time and quantize audio in logic using
flex time one of the cool extra features
of flex time is that we can actually
create tempo changes and make audio
files and audio recordings playback at
different tempos than they were
originally recorded so what I've got
here is a session with a one drum loop
at the top a audio file that was
rendered from the razer instrument from
Native Instruments and then on the
bottom I have a software instrument that
is just MIDI data so let's listen to
what this sounds like
you
okay so let's say that we want to change
the tempo of our project and we want all
three tracks to conform to the tempo
change that we make a couple things to
keep in mind here first the MIDI data at
the bottom here on our software
instrument will always conform to the
tempo change also our apple loop appear
on the top will also always conform to a
tempo change now the way you can tell
that this is an apple loop is you'll see
two circles with a line under it as
opposed to this region where there's two
interlocking circles which just means
it's a stereo audio file so audio
regions that are not loops will not
conform to tempo changes so let's just
give this a try let's go up to our
transport and what we're going to do
here is we're going to change our
initial tempo from 125 and we're going
to change it to 150 to make it faster so
just double click and type in 150 so as
you can see the middle track has gotten
longer and the upper and lower tracks
have not and what's actually happened is
that the upper and lower tracks have
gotten faster and conform to the tempo
change while the middle track has not
now the reason why this happens is that
audio files other than Apple loops have
a fixed time base of samples which in
this example essentially means that even
if you change the tempo the position of
each of these samples in the audio file
stays the same
whereas Apple loops and MIDI data have a
relative time base so they'll adopt the
new tempo
so you can hear that the upper and lower
tracks sound fine let's add the middle
track back in
yeah you can hear how the bass line is
falling way out of time with the other
two instruments so we need to do is we
need to have the middle track change its
time based two ticks which is a relative
time base much like the apple loop much
like the MIDI data below it so the way
we do this is you just turn on flex time
by clicking right here and I'm going to
use the flex time automatic algorithm
which automatically figures out what the
best algorithm is for us and here it
shows that polyphonic is the best
algorithm
and as I showed you before remember that
when you use polyphonic it's always best
to turn on the complex option in the
track parameters and you'll also see
that the waveform has a bunch of
transient markers in it you can pretty
much just ignore those because as long
as you've chosen a Flex algorithm you
can change the tempo to whatever you
want
it'll conform that entire region to the
new tempo so I've changed the tempo to
150 bpm and let's listen to what this
sounds like
all right that sounds great the middle
track fits in nicely with the tempo
change and the other two tracks let's
try a more like laid-back feel let's try
80 bpm
all right so that's not pretty good you
probably heard in the drum loop
especially that some digital artifacts
were produced from the time expansion
and that's to be expected anytime you
push the tempo up or down anywhere from
about 10 to 20 BPM you are going to
experience and hear some digital
artifacts produced from the time
compression or expansion so next let's
talk about how to change our tempo
across time let's say that we want to
start at a lower temp oh and then slowly
increase to a faster tempo what you can
do is you can show your global tracks by
clicking here or by pressing G on your
keyboard and one of the global tracks is
the tempo track what we can do the tempo
track is we can change our tempo across
time from a fixed tempo to a moving
tempo and Apple loops and MIDI data as
well as our audio file down here that
has flex time applied to it will conform
to that tempo change so the way you do
that is essentially this line is just
automation you double click on it and
you can create 2 tempo points and I'm
going to pull this up here to a faster
tempo
so let's say 158 and let's pull our
first point down to a slower tempo
so we'll go with like 80 so what's going
to happen right now if I leave it as is
it's going to play the whole thing at 80
and then just abruptly jump to 158 what
we're going to do is grab this little
point here this little node here and we
are going to change the arc or the curve
of the automation so that we can have a
gradual tempo change that goes from 80
BPM to 158 BPM now you can also use this
to create slowdowns as well and it also
works for any audio track as long as you
turn on flex time like I did before
all right so you can hear there that all
of the tracks in the session sped up to
the tempo change that I made and this
essentially lets us create what's known
in concert music as in accelerando a
speed up or Ritardando which is a
slowdown so what we do is going to go to
my list editors I'm going to show you
one more way we can do this in the tempo
list one thing that you can do is you
can create a fixed tempo change rather
than a gradual tempo change and what you
can see here is that right now at
position 1 1 1 1 we have a tempo of 125
bpm it's basically just denoting the
original tempo of the project
so basically what that means is that bar
1 or measure 1 we have a beat 1 and then
we have division 1 and we have tick 1 we
have a tempo of 125 so we can add in a
new tempo change by clicking right here
and what it's going to do is it's going
to create a tempo change wherever your
playhead is so right now I play heads
that measure 10 so I click the plus
button it says hey we have a new tempo
change at bar R Bar 10 beat 1 division 1
and tick 1 so I'm going to double click
on the tempo there at bar 10 I'm going
to change that to say 150 bpm so what
this means is at measure 10 the tempo is
going to immediately change to 150 bpm
we can also check this in the global
tracks and you can see there that the
tempo will immediately change it measure
10
all right so that's how you can create
tempo changes with tempo automation flex
time and the tempo list now I think in
the last video I think I said that I was
going to cover flex pitch next in
episode 22 now in episode 22 I actually
have one more topic I need to cover
concerning tempo changes and we'll be
talking about a function in logic called
varus speed which is pretty cool so
we'll I promise we'll finally get to
flex pitch by episode 23 so I hope you
enjoyed the video and thanks again for
watching