American Transcendentalism has many philosophical overlaps with the spirit of metal, if a bit on the dreamy side. IMO Emerson is the best of the bunch: practical, insightful, with a masterful use of English.
Following are his works:http://www.emersoncentral.com/texts.htm
Public domain by now, so feel free to do as you please with them. I highly recommend starting with "Experience" from the second Essay collection. I recall "Self-Reliance" from high school and it stuck with me, hopefully some of the younger members here can enjoy it as well.
A few good quotations, not necessarily from the above essay:
"Every word was once a poem."
"We have learned that we do not see directly, but mediately, and that we have no means of correcting these colored and distorting lenses which we are, or of computing the amount of their errors."