I got my 1965 Mustang with lots of dings & scratches. It had already been refinished with the original Dakota Red, so some of the vintage value was lost forever. I decided to refinish it in a nice natural wood tone like the headstock. When I stripped it, woops!...now I know what Poplar is!
The Poplar is dark brown in some places and light tan in others, like it's made from several different species of wood. Also it's very soft so it sands easily...no dings left now. But I see how easily Poplar can get dinged.
And porous Poplar sucks up stain unevenly. Luckily I learned about this before getting too far into the project. Instead of liquid stain, I applied Butternut Gel Stain to the brown wood to lighten it a bit. Then I applied Autumn Gel Stain to the light wood to darken it a bit. Gel Stain does not soak in so it tints the surface of Poplar more evenly than a liquid stain could. Sanding the Gel Stained wood lightly with 0000 steel wool brought the two Poplar colors closer together.
Then I sprayed Fender Neck Amber (from Guitar ReRanch, Texas) in very thin coats. This has brought the brown and tan sections even closer together, nearly matching the headstock, the look I was shooting for. I discovered I could continue to lighten the darkest sections by applying a a poly clear coat then a second coat of gel stain over that (applying coats of gel on top of each other didn't seem to have any cumulative lightening effect, as if the new coat rubbed the prior coat off). Next I'll apply a satin nitro clear coat (from Guitar ReRanch) which is tinted just 20% as much as the Neck Amber to soften the contrast a bit further.
The guitar now looks in really good, clean, well-cared for condition. Not a classically beautiful piece of wood, but it's handsome with unique character.
Regarding the woods-tonal difference discussion, here's my two cents. I'm no expert but I have been doing some peeking into the scientific research on solidbody electric guitars this past year. The hard science seems to come down to this: tonal differences based on the wood are sometimes detectable by scientific instrumentation in laboratory conditions. These differences tend to be beyond the range of ordinary human hearing.
The down-to-earth reality is that placebo effect is real...when we believe we'll hear a difference, we really will...so everyone wins.
I'll upload some pictures when I'm done.
Doug