Connect an audio interface to your computer. The audio interface converts the audio into data so that the DAW can interpret it. Depending on the make and model of your audio interface, connecting it to the computer calls for either a Firewire or USB cable.
Connect the female end of an XLR cable to a microphone. Connect the other end of the cable to the XLR input socket on the front of the audio interface.
Open your preferred DAW. Double-click the desktop icon. Typically the last recorded session opens automatically. If this isn't the session you require, click "File" and select "Open Recent." Select the relevant session from the drop-down menu.
Hit "Play" on the DAW interface and have the singer listen. There may be some elements of the backing track that are distracting, such as guide vocal takes or unmixed guitars. Remove these from the backing track by clicking the "M" icon on the channel strip for each instrument. This temporarily mutes the channel. Since this process is intended to emulate karaoke singing, it's essential to remove all distractions.
Click "File" and select "New Audio Track." Name the track "Vocal 1."
Tweak the backing tracks. Have your singer sing along to the backing track. If there is anything that is too loud or too quiet in the mix, use the gain sliders on the channel strip to correct the levels.
Connect a pair of headphones to the rear of the audio interface. This is the only element of the recording process that differs slightly from karaoke singing. It's essential to use headphones; otherwise, the singer won't be able to hear the backing track. You can't play the backing track through speakers; the sound will spill onto the microphone.
Audition the headphone mix. Hit "Play" and have the singer perform along. If the mix is too loud, turn down the "Monitor Level" dial on the audio interface. Turn it up if the mix is too quiet.
Audition the vocal microphone. Have the singer sing into the microphone. Monitor the volume units level on the DAW interface. If the volume units meter flashes red, reduce the "Gain" dial on the audio interface. Aim for the loudest possible gain level before the meter flashes.
Hit "Record." Let the the backing track roll as the singer delivers her take. When finished, hit "Save."