Funny Shapes (Part II)

In the previous post of this series I wrote about how Chronotron can detect and classify transients, which are then shown on top of the waveform using different shapes. In a nutshell, this feature provides you with visual clues about musical events, like note attacks, which may not be obvious to spot by looking at the waveform alone.

There are a couple of ways to use this information to your advantage. In today’s post we’ll have a look at concrete examples.

Aligning markers or loop points

You can double-click on a marker or loop point on the tracking ruler to align its position to the closest transient.

It’s as simple as that. The following animation shows this feature in action.

Note that, for markers and loop points to be editable in the ruler, the player needs to be paused or in Hold mode.

Beat detection

The Click Track tab in Chronotron allows you play clicks at a defined cadence together with the file. It’s like a metronome, except that the clicks are anchored to their beat locations, which has a few interesting implications:

• If you change tempo, key or playback speed, the clicks will also change accordingly
• If you jump back and forth within the file, the clicks will still be where you left them. This is why clicks can remain in sync when playing a loop, even though the loop points may not be perfectly timed.

The challenge is, of course, to synchronize the clicks with the file being played using the two available parameters: Tempo and Offset.

What Tempo means in this context, expressed in beats per minute (BPM), should be clear. Offset is when the first click plays, expressed as a percentage of the distance between two clicks.

It’s been generally accepted that, with a few caveats, tempo information can be extracted just from the transients. Yes, from the transients. Does that word sound familiar?

Chronotron can help you find out suitable tempo and offset values in a couple of ways.

You can do it manually – still, with the app’s assistance – by visually aligning the beat marks to the transients in the tracking ruler, as shown in the animation below.

This works while the player is paused or in Hold mode and the click track is enabled.

You can also let the app try to find the parameters automatically, either by looking at the full song or at the loop section (if loop points are set). That’s what the “light bulb” button does.

The suggestions flagged with a star are the ones most likely to work. The algorithm Chronotron uses performs well on a variety of material; however, because beat detection isn’t a trivial matter, your mileage may vary.

Do you use the click track feature? Do you prefer assisted or automatic beat detection? Let me know via the Comments section.