You can only play one song when you use the mobile phone music app wireless WiFi to cast the screen to the TV. As long as the phone screen is not black, it can be played continuously. If the phone screen is black, you cannot switch to the next song. The solution is as follows;

1. First, before mirroring, connect the smart TV and mobile phone to the same WiFi, and then open the music software on the mobile phone, as shown in the figure below.

2. Find the music you like and start playing it. Click the "Cast" icon in the upper right corner, as shown in the picture below.

3. Then in the pop-up casting type selection box, select AirPlay or DLNA, as shown in the figure below.

4. Then check the TV you want to cast the screen to, as shown in the picture below.

5. At this time, you can see the screencasting as shown below, and the screen casting is completed.