Determining the tempo of an audio recording

When working with audio in Cakewalk, you might find it helpful to have the measure boundaries line up with the beats of your audio recording. This is particuarly useful when working with drum loops, but can also help you with your editing work. If you don't have an application that can calculate the BPM (Beats Per Minute) of audio, there is a mathematical method you can use.

As as example, let's use the file Riff Funk Audio and MIDI Demo that comes with Cakewalk. Open that file, and you'll see the tempo of the song is 113.86 BPM. Let's see how we could have determined that tempo if we didn't already know what it was.

Let's select the first clip in track 2, as it contains four beats (you can tell this by listening to it). Open the Event List for this clip and you'll see the number of samples listed: 92949.

If the sampling rate of the Cakewalk project is 44.1kHz, as it is in Riff Funk, we know that there are 44100 samples played every second. We also know there are 60 seconds per minute. Finally, we have 4 beats in the selection.

Therefore, multiplying the number of samples per second (44100) by the number of seconds in a minute (60), and then multiplying that by the number of beats in the selection (4), gives us the basis for our equation.

44100 x 60 x 4 = 10584000

We then need to divide that number by the number of samples in our selected audio loop.

10584000 / 92949 = 113.86

So the tempo (BPM) of the audio is 113.86. We can now place that number in Cakewalk's Tempo field, and the measure boundaries will line up properly.

You can now apply this technique to your own audio recordings, filling in your numbers in the equation:

1058400 / (samples in the audio clip) = (tempo of the audio clip)

Good luck!