Flex Time is a Logic Pro tool that uses Slice technology to help you piece together separate tapes with different rhythms. It allows you to cut up your recording into rhythmic slices, and then re-time those slices without affecting the rest of the piece. In this online tutorial, explore Flex Time and learn how to use it effectively in your recordings.
Have you ever recorded a tape where the feel and spirit of the performance is right on but the rhythm is lacking a little? In this movie, we'll explore how to use Flextime to conform an out of time audio recording to your song. Flextime uses Slice technology much like some other well known applications like ReCycle or Ableton Live. Allows you to basically slice up your audio into rhythmic slices. And then retime those slices without any resampling or destructive processing. Let's take a listen to this song. Especially pay attention to the wah guitar track.
(MUSIC) So as you might have heard, the wah guitar track got a little off rhythm especially between bars three and five. And then it kind of fell back into rhythm. We can use Flextime to fix this cause we thought the performance was pretty inspired, it just need a little rhythmic help. So first to make the wah guitar track rhythmically flexible, we need to enable Flex mode.
We can double-click on the wah guitar region to open the Audio file editor. I'm going to pull this up and make it nice and big. Now here in the audio file editor, we have this button up here, and this is called Show Hide Flex, it's kind of like a twisted audio region is the icon in there. So the first thing we need to do is enable Flex for this wah guitar track. So I'm going to click here, and it's going to ask do you want to turn on Flex for the track? And then say yes. Let's turn on Flex for that track. So now, we start to see those slices I referred to earlier. It's slicing up our wah guitar track. Now, there's not one universal slicing algorithm for every sound.
So, there's actually a menu here that gives us some different options, depending on what kind of sounds we're trying to slice up. The first thing to know is that, if you have Flextime automatic checked. Logic will automatically choose the slicing algorithm it thinks is best for this region. And I want to kind of just talk about some of these algorithms, and what they're best for. The one that Logic thought was best for this particular region is Monophonic. And that's used for anything, like a bass line, or even this wah guitar is a monophonic guitar track.
When you use the Monophonic flex algorithm your recording should be relatively dry without any audible reverberation. So that is one option we could chose for this wah guitar track. We also have the slicing mode, and this is really good for percussive non-tonal audio material like drums for a example. Slicing cuts up the audio material at transient markers And then shift the audio when playing each slice at its original speed. In other words, no time compression or expansion is applied to the shifted audio. There's also the Polyphonic mode, which is really good for chordal material, or complex material.
It uses a process called phase vocoding. A process that uses phase information to time-stretch an audio signal without touching its pitch. It's the most processor intensive of the Flextime algorithms. And then we have rhythmic. Rhythmic time stretches the material looping audio between slices in order to fill any gaps. This algorithm is most suitable for materials such as rhythm guitars, keyboard parts, and apple loops. So, it's a little bit of trial and error here but let's start out for this track with a rhythmic flex time and, by the way, these other two down here speed in tempo phone, they use pitch shift as they stretch.
And you can use those for special effects. Tempo phone, for example, is the effect of a historical tape based time stretching device. But, we're not going to use those for this because we want to do something a little bit more transparent than that. Let's start with a rhythmic flex time. So once you choose your algorithm, then you can zoom into your track and we can start to re-time where these rhythmic slices land. As you can see, some of the rhythmic slices aren't exactly on the grid. So we're going to start to pull them back and kind of conform them more to the tempo. Before we do this, I want to actually turn on our metronome, then we can hear at least a rhythmic reference as we're working.
The next thing I want to do is just make a cycle between bars three and bar five, because that's the area we're going to be most working on here. So, I'm just going to zoom way in. Again, just make our view nice and big so we can see what we're doing. And let's just use the Play button here in the Audio file editor that lets us hear just this region. Let's hear it. Again, we haven't done any movement yet. Let's just check it out again. (MUSIC) Okay so it's a little offbeat. The idea here is you wanted to start pulling some of these transients so they're a little more on beat.
See I just pulled that one over, might want to pull this one back a little bit, and start kind of shifting them just so they get a little on beat, and it's one of those trial and error things, but. And just start kind of conforming it to the grid, as much as I can. This one threw a marker there, where there isn't really too much of a rhythmic thing, so I'm just going to ignore that one. It's pretty intuitive, once you start moving these around. And you start, just sort of aligning these up. And some of them might end up being off beat. By default. You don't want to stretch things too much because then you'll really start to hear the algorithm at work, but let me just make some of these, and let's see how far we can get just by visually adjusting these rhythmic variations to the underlying grid, which I'm looking right up at the top of this Audio file editor to see.
So let's check this out and see how this sounds. (MUSIC). Pretty good, there's a little thing at the end there, I noticed it gets a little weird here. We can maybe pull that out, try to make it land on the beat. So let's hear that one more time, bring back a little bit. (MUSIC) That's pretty good for starters.
Let's check it out with the context of the song, so let's hear it with everything else. (MUSIC) And that works awesome, so that Flextime allowed us to just, go in there and seamlessly stretch and shape the wah guitar rhythm, and now it matches right in with the track and it's like the performance just was played perfectly. And the cool thing about using Flextime is at any time, see I can click on the track header to select a track, and if I go in the Track inspector here, you can see that Flex mode is enabled as rhythmic, but you know, any time you can go in here and just say oh let's hear it, turn it off.
I don't want to hear it for a second. And you can see the audio waveforms just shifted back to get back to the original played performance. (MUSIC) And now it's back to it's off time rhythm, but I can then go back in here, turn it back on to Rhythmic, and it's shifted back to how we had it. (MUSIC) So with the magic of Flextime, Logic makes audio act almost like it's MIDI where any performance can be retimed without any intensive reprocessing or loss of audio quality that usually is associated with time stretch processing.
It's really powerful stuff. You can feel free to use Flextime on vocals, base, guitars, drums, any sound that you need to lock into the groove better.
- Exploring templates
- Controlling playback
- Making beats with Ultrabeat
- Jamming on the iPad with Logic Remote
- Recording MIDI in separate takes
- Quantizing MIDI performances
- Creating Apple Loops
- Recording live performances
- Composing in the Score Editor
- Scoring music to video
- Mixing with patches
- Adding reverb and delay
- Bouncing down your mix