- Click on your form. Then right-click in the Toolbox and select choose items.

- Select the tab COM Components. Then check the option Windows Media Player.

- At the top of your form import the required library by typing using WMPLib below the other libraries.

- Copy your .MP3 file into your
bin/debug/net${dotnet-version}
folder.
- Where every you want to play the sound use the following code but replace
DiscoTrack.mp3
with your sound file.
WMPLib.WindowsMediaPlayer wplayer = new WMPLib.WindowsMediaPlayer();
wplayer.URL = "DiscoTrack.mp3";
wplayer.controls.play();