To select the tempo at which your music plays you may use the Tempo Change menu option from within the Viewer Window.
You can control the tempo by using the slider, typing the desired tempo into the text box, or by selecting a relative tempo factor using one of the buttons. The selected tempo is relative to the base tempo of the piece. Please note: If the piece has a notated tempo change (e.g. a ritardando), the notated tempo change will still apply during playback.
You may return to the original base tempo at any time by selecting the x1 button.
When you exit the Viewer Window, the tempo you chose will be retained for the next time you open the piece (even if you sign out, close the app, or remove the song from your computer). You can change the tempo both during Playback and while stopped.