least harmful light dimmer

If the kitchen and listening room are on different circuits it will not matter.

Dimmers go a bad name for causing noise when they were a new thing. With those sold today I experience no problems. I even have one on the light over my turntable, and I can't tell from the sound if it is on or off.

Ditto Lutron.

They were the first dimmers that didn't radiate RFI all over the place (even their line cord dimmers are quiet.) Naturally, they cost the most too ;-)

Lutron toggle dimmers. I'm a designer with two showrooms. We recommend Lutron exclusively UNLESS the lighting source is LED. There's a different quality (but expensive) dimmer for that.

In fact, we put in Lutron toggle dimmers wherever there is lighting.

When we create media rooms we always isolate the lines in a manner that eliminates line interference. We use Lutron toggle dimmers in these living spaces.