It's steel and retro.
For steel and retro, pick up a classic steel hardtail. Run 1x9 gearing and an older XC wheelset with 1.4 or 1.5 slick tires, and it will be plenty light and fast. Rigid steel fork of course.
"The song of a bird…We used to ask Ennesson to do bird calls. He could do them. How he could do them, and when he perished, along with him went all those birds…"-Return from the Stars, Stanislaw Lem
"We just walk around, and sometimes we go out and dance, and then we listen to the environment."-Ralf Hutter, Kraftwerk