Beat Mapping MIDI Regions

The following section takes a look at the beat mapping procedure in the Arrange window. Beat mapping is also possible in the Piano Roll Editor, Score Editor, and Hyper Editor, where you have the added advantage of directly seeing the corresponding notes. To use (or test) beat mapping, you’ll need at least one MIDI region that doesn’t fit the current tempo. You can simply record one without a metronome click, if none are available.

In the upper part of the Beat Mapping track, you can see a ruler which contains a graphical representation of musical bars, beats, and subdivisions. These reflect the division value set in the Transport bar (and are also dependent on the current zoom level).

To allocate note events to particular bar positions
  1. Select the regions that you want to use for beat mapping.

    Once selected, short horizontal lines appear at the lower edge of the Beat Mapping track. These represent the notes in the selected regions.

  2. Starting from the left, click-hold the first bar position in the Bar ruler that you want to assign to a MIDI note.

    A yellow vertical line appears.

  3. With the mouse button still held, drag the cursor down toward the line that represents the chosen note.

    A second, slightly darker, yellow line—which is still connected to the same position in the Bar ruler—appears. This line follows the movement of the mouse cursor into the lower part of the track, forming an angle. Once this line is connected to the desired note, release the mouse button.

    Figure. Beat Mapping track showing cursor being dragged from Bar ruler to chosen note.

    Logic Express automatically calculates, and inserts, a tempo change, which can be seen in the Tempo track. This ensures that the allocated note (and all other notes) will be played back at the same absolute time position as before, despite their altered bar positions.

  4. Move from left to right, adjusting further events along the time axis, to obtain the best beat mapping results.

    If you make a mistake, you can erase any beat allocation by double-clicking it, using the Eraser tool, or by selecting it and pressing the Delete key. Take care when using the Delete key, to avoid the accidental deletion of other currently selected events or regions. To erase all beat allocations, click anywhere in the track header of the Beat Mapping track (except on the buttons and menus). This selects all data in the track, allowing you to press the Delete key to delete all events.

Note: If you want to draw a connecting line from a bar position to a particular position in the original recording—where no note exists—hold down Control while drawing the connecting line with the mouse. This will allow the line to snap to any subdivision.