This just started the other day on my steel Davidson. Mostly happens on descents or on flats with a tail wind in those rare moments when I get above 20 mph. I hear a faint, tinny rattle coming from somewhere in the front of the bike. The spokes seem tight and all have the same sound when plucked. Front brakes seem ok, nothing loose there. Any ideas?

Look for anything loose or a cable end beyond the pinch bolt, and close to the brake or frame. With the right vibration input , the tip can vibrate enough to make contact and noise.

Check the skewer and hub. Do you feel anything vibrating? Is there anything mounted to the bars?

I have a Davidson myself, one of the few in the NYC area. I had it built when I lived in Seattle 33 years ago! I haven't been on it in a while, but I need to take it for a spin. It isn't sitting unused though, my son rides it.

zacster - There is a light mounted to the bars. Tightened it, and one brake pad, as well as a bottle cage. The last time this happened, now that I remember it, it turned out to be a bottle cage. I'll take it out tomorrow through a long descent; should be a good test.

FBinNY - pinch bolt on brake cable is really tight, but the cable end protrudes about two inches. I'll try putting a dampener on it if the noise persists. Good theory.

i had the cat whiskers on the tires hitting my fork tines that made a sound as you describe. like your noise, it would only be audible at high speeds and low ambient noise. a rare combination to be sure.

Make sure that your shoelaces tips (aglets) are not "tinging" against the frame or crank/chainwheels.

Those things are(were) tire savers, i'd mount them on the leading edge of the front fender & on the rear one. Shoelaces and front derailer touching. Any moveable parts. One bike I had rode it before and after was. The pedal spindle threads, installed and rode with & without grease. Dry sounded like a metal footbridge about to fail. Check under BB, grease it, Try brake mounting bolts, cable anchors. Chain needs , I used Tri-Flow 30 years ago. Could be Fork geometry. That's a separate question.
Try Bike Dued or Bianchi Girl. on Classic. I only ride & repair my own bikes. One last guess? Bottom bracket? I like greasing the Quick release skewer axles. They're fixed, and the wheel spins around them. Is the rear wheel tight enough? Sorry to broadcast a too long reply here, but bikes can Nag us. I get it fixed, in the repair stand, but you gotta ride it. Its just so nice when you're riding along, in an urban area,, its a nice solid quiet bike, passing, many slower cars. Chris