You can use Animate software to realize multiple scenes and share one music. You can follow the steps below:

1. Open a multi-scene Fla format source file.

2. Place the content of scene 2 into scene 1, and select scene 2 in the scene selection panel.

3. Use the mouse to drag to select all layers and frames. Note that the frames must be the same length.

4. Right-click and select Copy Frame and continue switching to scene 1.

5. Right-click on the frame at the last position of the timeline of scene 1 animation music and select Paste Frame.

6. After success, you can see that the animation music of scene 2 has been appended to the end of the timeline.