Audacity is a free professional tool for removing and isolating vocals, which is best for a stereo vocal track. Let's see how to isolate vocals in Audacity.
Step 1: Open Audacity and upload your audio song.
Step 2: Choose the soundtrack and navigate to the Track Control Panel.
Step 3: Convert the Stereo track to Mono by clicking Split Stereo Track.
Step 4: Choose the bottom track and click Effects > Invert.
Step 5: Delete the unwanted channel by clicking the dropdown arrow next to the audio file name.