Admittedly, a newbie. I want to bring in a previously recorded instrument track and record / add a new vocal track. It appears I must record the instrument track and then immediately record the vocal track (in one session). Isn’t there a way to open the pre-recorded instrument track and then record / add the vocal track? I have a Rode NT-USB mic. Audacity 2.3.2, Windows 10.
No, you can open an existing file first. Then Transport → Recording → Record New Track.
There are no time or content restrictions. You can use anything you want as a backing or cue track from a simple click track to a multiple track instrument and vocal collection. Or your own voice as many times as you wish. You want to be the Andrews Sisters? No problem.
There is Overdubbing and then there is Perfect Overdubbing. Perfect Overdubbing is where you hear your own live performance mixed with the backing track as you record. That usually requires that you plug your headphones into the microphone or the microphone interface, not the computer.
The Rode NT-USB has a place to plug your headphones, so without digging through the instructions, it seems that should work.
You should have good, sealed against the head headphones.
You don’t have to do that. You can record cold into the backing track and listen to yourself with your hand.
Gary Owens is being hysterically funny there (there are two microphones in that shot) but the effect is real. You make a tunnel with your hand so your voice goes up to your ear.