Join Damian Allen for an in-depth discussion in this video Editing audio like MIDI with the Flex Tool, part of Logic Pro 9 New Features.
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Since the early `80s, the Midi Protocols enabled keyboard players to change the pitch, speed, and amplitude of note data after the performance has been recorded. Digital audio technology has finally caught up to the point where we can now perform similar edits on recordings of live instruments like vocals and guitar. Logic Pro's method for performing these functions is called Flex editing. Now while it's similar to functionality referred to as 'elastic audio' in other applications, Logic Pro's implementation of the Flex toolset provides some unique and efficient ways to work with audio.
Let's dive right in. There are two ways to work with the flex system: using the Flex tool, or the Flex view. The Flex tool is perfect for quick tweaks to your audio, while you'll want to activate the Flex View for more extensive editing. In this lesson, we'll start by looking at the Flex tool. Here we'll take a look at shifting a Guitar's tab that was recorded ahead of the beat. In the Crash Chords track, Ctrl+Option+Drag to zoom around bars 21 to 26.
You can clearly see that at bar 23, the guitarist was a little over eager to hit the note, early by almost a quarter beat. To access the Flex tool, press the Escape key to bring up the tool pop up menu. Select the Flex tool from the list, or press the keyboard shortcut R. Now, click down anywhere on the audio region we're editing to trigger the Flex tool. Before you can use the Flex tool for editing, Logic needs to analyze the audio waveform for transients.
Transients are beats, or significant changes in amplitude, that logic detects in order to separate your audio into editable sections. Just so you know, this doesn't cut your audio up, although you can do that too. More on that in a moment. It simply creates markers for the Flex tool to use. To get started, you need to choose a Flex mode. If it's a percussive track, choose rhythmical slicing. Slicing will actually slice the audio into regions based on the transients.
If it's a solo instrument like a trumpet, lead guitar, or vocal, choose Monophonic. Although be careful with lead guitars, because often they'll have multiple notes. And if it's an instrument playing chords, such as the rhythm guitar we are working with here now, here we'll choose Polyphonic and click OK. If you look in the Inspector right now, you'll see additional Quantization Options. We'll cover the Quantization of audio in a later lesson. Now, position the Flex tool over the portion of audio you want to move, in this case the tab portion of the guitar just before by 23, and drag to the right.
Notice how the tail of the previous chord moves as you drag, but the start of the previous chord stays put. So does the start of the chord following the one we are adjusting. That's because they are anchored by their own transients. Line the start of the chord up with the start of bar 23, and release the mouse. And that's all there is to it. Play it back to review. We'll solo it first. (Guitar notes) And we can now hear that the guitar chord starts right up bar 23.
Let's have a quick look at one other handy feature of the Flex tool. We'll Ctrl+Option+Click to zoom out. And look at the situation where you want to move a whole phrase of audio around. In the past you'd slice up the audio, then move one of the new smaller regions around. Instead, select the Marquee tool. Then drag through the section of audio you want to move. Switch back to the Flex tool, and drag to reposition.
What's great about this, beyond the fact that you don't have to spend all the time removing silent sections of the audio region, is that the waveforms never cut. So you don't have to worry about clicks and pops created from nonzero point crossings. Now as we mentioned at the start of this lesson, the flex tool is useful for quick tweaks like this one, but for more complex editing you'll want to switch to the Flex View. In the Flex View, you can actually see the transient markers that Logic Pro created during the initial analysis, and add your own.
We'll take a look at the Flex View in the next lesson.
- Creating, moving, and deleting flex markers
- Adding effects and reverb to a created amp
- Importing and exporting tempo information from a session
- Building guitar tablature from the session
- Creating new groove templates