KORG CA-2 Chromatic Electronic Tuner
When I was younger, I thought that my ear was good, and that I could tune a kalimba (or a guitar) just fine without an electronic tuner. When I first moved to Tucson in 1995, I met a guitar player who wasn't really that good, but he always sounded pretty good because his guitar was always in tune. You see, he was an early adopter of the electronic tuner, and he used it each time before he played guitar,
When I realized that he often sounded better than me, I went out and bought a Korg chromatic electronic tuner. Not only did it vastly improve my guitar sound, but applying the tuner to my kalimba transformed my kalimba playing, essentially overnight. When your instrument sounds good, it inspires you to do your best to play music that matches the quality of your instrument. If your instrument is not in tune, it doesn't inspire you to greater heights. When your kalimba is in tune and it sounds great, it is asking you to step up to the plate and do your best.
The KORG CA-2 tuner has a digital display simulating an electrical meter, pointing to the left of center if the note is flat, to the right of center if the note is sharp, or right in the middle if the note is in tune. The display also indicates what note is being played, as well as the frequency reference of the A note. (More on that soon.) In addition to the simulated meter that indicates how flat or sharp a note is, there are also wto red lights and a green light that will indicate if a note is flat, sharp, or in tune. As the note is close to being in tune, both the green and one red light will indicate.
A very useful feature of the KORG CA-2 (and many other electronic tuners) is the ability to "retune" the tuner. When you first put in the two AAA batteries, the device will be set up to tune to a reference pitch of A 440 Hz. However, using the "CALIB" (ie, "calibrate") buttons, you can change that "A" reference pitch to anything between 410 Hz and 470 Hz - that is, more than a half step flat or more than a half step sharp. Why would you ever want to do that?
Well, not everything in the world is tuned to A 440. FOr example, a lot of healing musicians favor tuning to a reference pitch of A = 432 Hz. Why? Some people believe the music is more beautiful or more healing when pitched to that frequency. Or another use: let's say you are playing kalimba and guitar with an old piano that hasn't been tuned in a while. To first order, all the notes on that old piano will go out of tune in the same way, either flat or sharp, due to temperature changes. You can "tune" the tuner by changing the reference until the piano's "A" note is "in tune". Then, with that reference setting, you can tune your kalimba and guitar, and they will be in tune with your piano - or at least, in tune with the piano's "A". (If you are serious, test out several notes on the piano to get a "best fit" tuning calibration.)
One more feature: the KORG CA-2 chromatic tuner can produce a reference tone for A 440 Hz or Bb 466 Hz. Why? Orchestras tune to A 440, and concert bands tune to Bb.