A ClutterScore allows you to start and stop several timelines at once, or run them in sequence one after the other.

To add a timeline that should start first, call clutter_score_append() with NULL for the parent argument. All such timelines will be started when you call clutter_score_start().

To add a timeline that should be started when a previously added timeline stops, call clutter_score_append() with the first timeline for the parent argument.

Reference