I'm talking about adding or taking away treble progressively as a note rings.
You can ring a string unmuted and then slowly add muting as it rings, to give the impression of the treble decaying. Is there a way to do the opposite, start with a string muted (or use a bass string version of the note) and then make it start being trebly without re-sounding the note, and without taking away too much sustain too quickly?
Here is a simulation of the ramp up I made on a computer, followed by the ramp down effect which I just played by progressively muting: http://vocaroo.com/i/s0dcsg4IwFN0
Doesn't have to be exact, but any technique like this?
Things I've tried:
Playing the string muted, but then clattering a finger nail on it a little, to add some brightness. It's really hard (basically impossible so far) to get enough control of this, and also not stop the note ringing.
Playing the string muted, but then trying to progressively add fret buzz for the brightness. This is also really difficult to have any control over, and to not cause the note to stop sounding.
After more experimentation, you can half do it with a slide, or maybe if you had a ring on your finger. If you very briefly tap a ringing string with the metal, you'll introduce some brightness that stays with the string as it decays. It's not progressive though. You've got a muted string sound, and then you tap it, and the brightness is instant. Another drawback is that this will change the pitch. Probably doing it in key and very fast is better.