Select an audio track in the Storyboard or Timeline, then choose Audio Marker Assistant… from the Slideshow menu or the context menu in the Storyboard to open the assistant.

At the top you will see the audio waveform and playback buttons. You can scroll around the waveform. Use the scale slider or a two-finger pinch gesture on the trackpad to zoom into the waveform to reveal more detail.

The assistant has two different workflows: Automatic and Manual. Which one is more appropriate depends on the kind of music you are using:

  • Pop, rock, or dance music with a regular beat is suitable for automatic marker creation.
  • Classical music or soundtracks that often changes tempo may be more suitable for manual marker creation.

Once you click on OK, the slides above the audio item are automatically set to continue “At Audio Marker” and their durations are adjusted, so that animation speeds will stay the same.

Manual Markers

In manual mode you basically just play the audio and press the M key or the big button in the middle with the beat of the music to add new markers. Play the audio again from the start to review the accuracy of the markers.

If a marker is slightly off, then simply drag it to the correct location. Click on at the top of a marker to delete the marker. Markers are only used during playback if they are active. Click on the bottom circle of a marker to toggle its active state.

Automatic Marker Creation

Switch to Automatic if you know that a song has a steady beat (which is often the case for pop or rock music). Enter the BPM (beats per minute) value in the text field if you already know the tempo. The Offset value determines how far the first marker is positioned.

Moving Markers

If one or more markers are slightly off, you can reposition them in various ways:

  • Drag a marker line to move just this single marker
  • Press the key and drag a marker to move all markers at once. This is the same as adjusting the Offset value.
  • Click on the diamond shape of a marker to make this marker the “anchor” for the following step.
  • Press the key and drag any other marker but the anchor to spread markers in an equidistant fashion. This is the same as adjusting the BPM value.

Activating Markers

If you have a marker for every beat in a song that is obviously way too fast for switching slides. For this reason you should only activate a marker every once in a while. You get the most pleasing effect, if you know the meter of the song (e.g. 4/4 or 3/4) and then select if you want an active marker at every bar, every 2 bars, or every 4 bars.

You can also manually activate or deactivate markers by clicking on the bottom circle of a marker. An active marker will have a checkmark and is displayed in opaque red, while an inactive marker is transparent.

Syncing Slides

Adding markers to an audio track is the first step syncing slides with audio. The second step is performed automatically when you click on the OK button: All slides above the audio track are switched to continue “At Audio Marker” and their durations are automatically adjusted so that animation speeds are still correct.

Once you have added audio markers to your audio track, all you have to do is select all slides above the audio track, open the the Slide Options, and select Continue at Audio Marker. The slide transitions are now perfectly synced to the music!