Curves, similar shapes, dissimiliar substances

Today's title refers to the brim of the top hat and the curve of bell on the CG Conn Grand Jumbo 46K Sousaphone. I suppose the top hat is made of wool felt. And the tuba is made of silver-colored sheet brass. I know, I know. You thought I was going to point out that it refers to the top of the head and the curve of the bell on the golden CG Conn 20K. A toss up, which one to mention first!

I got the name of the tuba from two commenters on a previous post, one named Anonymous, one named Ian. Turns out that Ian is playing the CG Conn Grand Jumbo 46K Sousaphone! And Anonymous, actually Fred Williams is his name according to Ian, was playing a CG Conn 20K in the other post, standing between the two tubas you see here but facing towards them-- the one Ian is playing and to the golden one played by Johnny Quirarte of Los Culpables de la Sierra, according to Ian who is a veritable fount of information. Thanks, Ian!