Overdubbing+volume change?

I want to overdub while increasing and lowering the volume of the first track.
This is what radio DJ’s do - they talk (recording track 2) while playing music (playback track 1) and lower and increase the volume so that they can be heard and the beat keeps going.
And oh - I don’t want it to be done automatically due to latency, I want to be able to control the volume in real-time
Is this possible in audacity?
I hope my description was clear.
Thanks!

There is an Auto Duck effect.

Alternatively, you could use the Envelope Tool.