Extracting MIDI timing information from audio

Extracting MIDI timing information from audio allows you to:

Double an audio rhythm with a MIDI instrument.

Replace sounds in an audio clip (commonly used for drum replacement).

Notate the rhythm of an audio clip.

Align lyrics with an audio rhythm.

After you extract the timing information from an audio clip, the timing information is copied to the Clipboard as MIDI note events. You can paste the MIDI notes to a new MIDI track or use the Clipboard as a source for the Groove Quantize command.

To extract MIDI timing from an audio clip

1.	Select the Smart tool in the Control Bar.

2.	Assign the track’s Edit Filter control to Audio Transients.

3.	Press ALT+A to open the AudioSnap palette.

4.	Select the audio clip whose rhythm you want to extract.

5.	Do any necessary quantizing, and disable any transient markers that you don’t want to extract (see Quantizing audio and To disable a transient marker).

6.	With the clip still selected, click the AudioSnap Options button in the AudioSnap palette to open the AudioSnap Options dialog box.

7.	In the Convert to MIDI Note box, choose C3. This is the note most drum synths use for the bass drum. If your favorite synth uses a different note, choose it now.

8.	Choose a Note Velocities option: either accept the extrapolated velocities in the audio clip (the Vary With Pulse Level option), or set a constant velocity for the notes in the Set All to Same Value field.

9.	Click OK to close the AudioSnap Options dialog box.

10.	Click the Copy As MIDI button .

This adds the extracted groove to the Clipboard.

Cakewalk copies the audio rhythm to the Clipboard as a MIDI clip, with the same pitch assigned to each note.

You can now paste the MIDI notes to a new MIDI track, use the Clipboard as a source for the Groove Quantize command, or save the extracted groove as a Groove Quantize file.

To paste the extracted MIDI timing to a MIDI track

1.	Click the track number of a MIDI track to select it.

2.	Move the Now Time to the measure where you want the data (we’ll use measure 1).

Tip: If you want the MIDI notes to align perfectly with the audio data, press SHIFT+G to move the Now time to the beginning of the selected audio clip.

3.	Press CTRL+V to paste the data.

A new MIDI clip is inserted in the track

Note: All the new MIDI notes have the same pitch, and the tails of the preceding notes reach all the way to the following notes, so you can’t see the actual rhythm. You can easily shorten the duration of each note event in order to clearly see each note event. To do so, click Process > Length to open the Length dialog box. In the Length dialog box, disable the Start Times check box, enable the Duration check box, and type 50 in the Percent field. Click OK to close the dialog box. Assign the MIDI track’s Edit Filter to Notes and you will be able to see the rhythm if you zoom in.

To save the extracted MIDI timing as a Groove Quantize file

1.	Select Process >Groove Quantize to open the Groove Quantize dialog box.

2.	Click the Define button to open the Define Groove dialog box.

3.	In the File field, choose a file to save the pattern in, or type a name to create a new file.

4.	In the Pattern field, type a name for the pattern, and click OK.

The extracted MIDI groove is saved as a Groove Quantize file, and can be used at any time with the Groove Quantize command.

 

See:

Using global tools on AudioSnap transient markers

Editing transient markers

Using the AudioSnap palette

Synchronizing audio and the project tempo

Fixing timing problems in audio clips

Extracting MIDI timing information from audio

General editing

Using the Pool

Algorithms and rendering