I never warmed up to digital instrument tuners -- I find them ok, but dislike
the "nervousness" -- watching this little needle/lights twitch to and fro & settle.
All I need to tune an instrument is to hear some known pitch. Pitch-pipes
serve this purpose, but, for example, I own at least a couple of pitch-pipes
--- as to where they are in my rooms-full of junk, that's another matter!


Anyhow, I came up with this super simple, on-instrument pitch reference 
constructed from a few penny's worth of materials: one large-sized bobby pin,
one screw and a few bits of scrap wood. I super-glued this tiny thing 
permanently to the shell of my home-made banjo (players of fancy instruments 
may opt to attach it another way) & always have a pitch reference handy. 

If, of course, you'd rather not glue this thing to your instrument, you might
do as I also did -- I peeled-back a small bit of  "padding" from my fiddle case
-- down to the bare wood & likewise installed one on the inside of this case.
Just make sure it's in an out-of-the-way place inside the case.

I keep mine in the key of D (my very favoirite fiddling and clawhammering 
key) but obviously any note will work fine.

UPDATE a week later: Been experimenting along these lines.
I found that a reed from a discarded harmonica makes a nice "on-instrument"
pitch reference too. Less in-the-way than above bobbypin arrangement.
This photo is self -explanitory:


These harmonica-reed twangers, while not loud, can be easily heard when 
plucked. The tailpiece-mounted version is a considerably louder than the 
headstock-mounted version.

Dennis Havlena   Webpage at www.DennisHavlena.com

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