This is the playback tempo, in beats per minute. The document is played at this tempo, unless this base tempo is modified by a tempo track. The tempo can be changed at any time, including during playback. Changing the tempo may change the current time shown in the status bar. To change the tempo, left-click it, edit the value or type a new one, and press Enter or Tab, or left-click elsewhere. To increment or decrement the tempo, use the arrow buttons that appear when you left-click the tempo. For more information on editing, see the Properties bar. Fractional tempos are permitted.
Tempo is normally expressed as a frequency, but it can also be expressed as a period, in other words how long each beat takes in seconds. To compute the period, divide 60 by the tempo. For example, at 120 beats per minute, each beat takes half a second, because 60 / 120 = ½.
Tempo can be remotely controlled; see tempo mapping. During playback, the net tempo is shown in the status bar.