Timebase Rulers
Any or all of the following Timebase rulers can be displayed at the top of the Edit window and in MIDI Editor windows:
• Bars|Beats
Displays the Time Scale in bars and beats. Use this Time Scale if you are working with musical material that must align with bars and beats. The Bars|Beats Time Scale is relative and is affected by the project’s tempo and meter map.
• Minutes:Seconds
Displays the Time Scale in minutes and seconds. As you zoom in farther with the Zoomer tool, the Time Scale begins to display tenths, hundredths, and thousandths of a second. The Minutes:Seconds Time Scale is absolute.
In addition to providing a timing reference for track material, the Timebase rulers are also used to define Edit selections for track material, and Timeline selections for record and play ranges.

With the Selector tool, drag in any Timebase ruler to select material across all tracks in the Edit window. To include the Conductor tracks in the selection, press Option (Mac) or Alt (Windows) while dragging.