Do you answer the phone when you're playing guitar?
Definitely one of life's tougher questions...
I unplug the phone when playing. NOTHING interrupts playing.
And these days the robot callers seem to outnumber the live people about 10-1. They usually give "their" name to make it sound more like a real person, so I ask 'em "Dave (or whoever), are you a robot?"
Most of the time they keep talking which is the give-away right there, but occasionally one will say there's a live person available to help them. If they keep talking I just put the phone down and go back to whatever I was doing. Make 'em pay more money for the no-results call.
If they put the live person on the line I ask 'em why in the world they think I'd want to do business with a company that uses illegal marketing practices. (Robot calling is illegal here in CA)
But I had the most fun a couple of years back when a scammer called to say it was Microsoft technical support and they'd detected a security breach on my PC. I didn't own a PC at the time but I fell right into it:
"Ohmigod I'm so glad you called, I have a real weird problem!! When I turn on my PC green slime starts leaking out of the sides it looks just like snot. So I opened it up and there's all these little bugs inside. They look kinda like little tiny crabs with batwings. Do you know what they are?" (click: hangs up)
Never heard from 'em again.