How to Sync Music Files with Sony Acid Project Tempos

Take any music and match its tempo with Acid – or vice-versa

by Craig Anderton

Although beat-oriented programs like Acid and Ableton Live usually use relatively short loops to create projects, you’re not limited to that option: It’s possible to “beatmap” long, unlooped files so that they can match up with the project tempo. This works by importing the file you want to beat map (even ones with slight tempo variations will work). You then add markers so that the file plays back in sync with the rest of the project, or the project tempo syncs to the file.

So how does Acid know what’s a “long file” instead of a loop? Acid’s default is that it assumes files over 30 seconds are not loops, but you can change the default time under Preferences > Audio Tab, in the top right field.

Here’s how to do it.

Fig. 1: Choose the file you want to beatmap.

First, drag the file you want to beatmap into an Acid track. Acid supports drag-and-drop from the desktop if you like to roll that way.

Fig. 2: The Beatmapper wizard appears.

Upon loading the file, Acid’s Beatmapper wizard appears. When it does, click Yes, then click Next.

Fig. 3: Identify the file’s downbeat so Acid knows where the music begins.

Next, move the downbeat marker to the file’s first beat, then click Next. Note that the Play and Stop buttons let you audition the file shown in the Beatmapper so you can make sure you’ve chosen the right place in the file for the downbeat.

Fig. 4: Tell Acid the length of a measure.

The Beatmapper wizard now estimates the length of one measure. Adjust the end marker to define the exact end of the measure. Zoom in if needed with the (+) button to position the measure end as precisely as possible, as Acid needs this data to map tempo properly. Note that you can enable a metronome sound as a rhythmic reference if you find that helpful.

Fig. 5: Verify that you’ve created a loop that loops seamlessly.

Click on the Play button to verify that the highlighted region loops correctly, then click Next. If the loop isn’t right, re-adjust the markers that define the loop.

Fig. 6: Apply a similar process to identify the other measures in the file.

Next, click on the Play button again, then click on the > button (or click within a measure) to step through each measure and verify that its start and end points are set correctly. When they are, click on Next.

Fig. 7: Success! The file is beatmapped.

The file is now beatmapped, and the wizard shows three options: Change Project Tempo to Match Beatmapped Track (if unchecked, the Beatmapped track follows the existing project tempo), Preserve Beatmapped Track Pitch When Tempo Changes, and Save Beatmapper Information with File. Check the desired options, then click Finish.

After the clip is beatmapped, you’ll want to save these changes. Click on the clip, then click on View > Clip Properties; next, click on the Save button to embed the Acidization information in the file. At this point you can also click on the Stretch tab for beatmap editing without having to invoke the Beatmapping wizard.

Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.