In AudioDirector’s mix room, you can record audio directly over an existing track.
Connect a microphone to your computer and select the recording device from the drop-down menu in the mix room. You can also configure other recording settings in this room, including the backtrack volume.
Add the backtrack without vocals to your audio editing timeline, and make sure that the timer is at the start of the track.
Next, click the red record button. There might be a countdown timer before the recording starts depending on your recording settings. You can record your vocals with the music track when the recording starts.
Stop your recording.