steps: 1. first, open the fast tour application on your mobile phone and click the video clip icon on the main interface. 2. then, on the opened album page, select the video to edit. 3. Next, on the opened video editing page, locate the location where you want to add music. 4. Then click the music icon at the bottom of the page. 5. Then click the music button in the open toolbar and select Scroll Music to finish.