Apple Logic Express 9 - Manual (Page 1029)

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.
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.
1029 Chapter 34 Beat Mapping Regions