D and B. David Bowie, Drum and Bass or the letters I always used to mix up as a kid?

I like the pattern of repeated circles on the inside and outside.

I like the way the line zig zags through the piece.

I'll make it without any solder joins, and will tidy up the interlinks and maybe design them to be more of a feature

I'm pretty sure the copper solder I used for this rusts. Which is quite shit really.

I just looked it up. The stem of the d or the b is known as a 'chord' in mathematics so it has to be something musical. http://www.mathopenref.com/pictorialindex.html