I’m thinking things like harp and marimba
You can really feel the waves of sound
Cathedral pipe organ. Pull all the stops.
This is the answer. The entire cathedral is part of the instrument!
Low brass will rattle your bones if the musician pushes enough air. It’s basically the sound of reality ripping in half.
…we need some symphonic metal that highlights full-power low brass - like it’s literally the most metal sound an instrument can make. I mean, guitars are great and all, but BWAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!
A good handpan in a quiet room will, especially stainless steel ones.
Synths with big unison lol
Glass Armonica. Story goes it would drive people mad!
Sitar and hurdy-gurdy both use drones to get this quality.
Butt trumpet
Electric guitar into a full stack.
bells
Tuba, French Horn, Carnyx, Timpani
This is primarily keyboards/synths but when I think of resonance, this is wonderful. Crank it up.
