Step 1: Connect all karaoke music, including backing track with lyrics and singerless backing tracks, to your PC.
Step 2: Open MusicBee app on your PC and import those karaoke songs.
Step 3: Right-click on the karaoke song and select the option "send to > external device".
Step 4: Next, select your headset as the output. That way, you can hear song with vocal on your headset.
Step 5: To send song without vocal to the audience. Right-click the same song again, go to "send to", and this time select your speaker.
For Mac Users:
Step 1: Open Music app on your Mac.
Step 2: In the menu bar at the top of the Music app window, select "File > Open Audio file" and select the karaoke song.
Step 3: Control-click the song in your Mac Music library, and select Get info.
Step 4: Click on the options tab > check the box next to "ignore volume settings".
Step 5: Now connect a second pair of wired headphones to your Mac through the headphone jack.
Step 6: In System Preferences > Sound > Output. You will see two headphones appear. The internal headphones connect to your AirPods, and the external is for the wired headphones you connected.
Step 7: Make sure the volume of your internal headphones is all the way up, and the volume of the external headphones is all the way down. That way, you can listen to the song with the vocal using AirPods.
Step 8: To send the instrumental to the speakers (assume that is connected via Bluetooth), go to System Preference > Sound > Output. Select the correct Output device (eg. AirPods Max). Adjust the volume so that it's a comfortable level.