Fevered pitch

I’ve been trying to find the origin of the phase fevered pitch. Does anyone know?
You guys are my best hope. I’ve looked everywhere I can think to look.
thanks,
ruby

Fevered means, in addition to having a fever or being physically heated, (in the words of the OED) “of the mind: excited; over-wrought.” But I can’t determine exactly what connotation of pitch this uses, or to what it would have referred. I’m curious to find this out myself now.

I’ve heard and seen it rendered “fever pitch,” not “fevered.”

Perhaps that will make it easier to find a website that discusses the etymology.

–Cliffy