Metal, aluminum, or wood for a rack ?

If you search for Wood racks I think you will find my comments. If you can't in summary using steel rods with appropriate stop nuts and end caps thick Maple makes an excellent vibration damping rack.

The rack I built is rock solid, and I was walking on top of it when I put up some track lighting. Mapleshade uses 1-1/2" steel, so imagine how rigid that should be?

I used 3/4" brass because that's the heaviest I could find. Why? Some say it sounds better than steel, but that could be just a bunch of baloney. I like how it looks, but expensive.

I built my rack with Pennsylvania slate shelves. If I could go back in time six or seven years I would get thicker all thread. That being said, I can stand on my rack also with no wobble. As for vibration, rap your knuckle on a 1 1/2 inch thick piece of slate and you get nothing but pain.
I loved the look of the slate when I built it but would probably like something a bit more refined now.

Elizabeth.
You're freaking me out man.