The four cities' names begin with "ABCD". Brief colours and typefaces are used in this motion design. Some representative architectures in those cities are chosen to connect every scenes.

The background music information:
Dreams by Firefl!es https://soundcloud.com/mangesh-dongar...
Creative Commons — Attribution 3.0 Unported — CC BY 3.0
Free Download / Stream: http://bit.ly/dreams-fireflies
Music promoted by Audio Library https: https://youtu.be/UD0-KV3SoGI