In addition to altering the tempo when the song switches from e.g. intro into verse, it is also very handy to have a clear indication of more general changes or special events in the song. For this purpose you can also add Tags to the song. These Tags are short text messages you can add at the beginning of a column. They will be shown in the Director whenever the playhead passes them.
To add a Tag, you can either left-click the bottom of the Timeline or middle-click Timeline or Song Ruler. A dialog will pop up that allows you to add text for any bar.
Once you are done you will see a small T at the bottom of the Timeline and can view its content by hovering over it.