Use a Korg tuner to get an instrument into perfect pitch. Musical instruments go out of tune whether they're played or left idle. Korg makes electronic tuners that offer two ways to arrive at the right tuning. The Korg CA-30 will sense the correct pitch for each note and show you when when your tuning matches, or it can play the correct pitches for tuning by ear. The Korg CA-30 is very popular for use as a guitar tuner.
Insert two AAA batteries. Open the Korg tuner by pinching the side tabs and pulling the bottom cover off to access the battery compartment.
Prepare the Korg tuner and the instrument for tuning. Turn the tuner on by pressing the red power button. Plug the guitar or other musical instrument into the tuner with a 1/4-inch mono jack, or hold the guitar near the built-in microphone on the tuner.
Check the tuning. Pluck any open string on the guitar. The tuner will show a letter identifying the nearest note to the pitch. The needle on the view screen will rest to the left of the center if the note is flat, or to the right of the center if it's sharp. A red indicator light will also glow on the left or right depending on the status of the note. If the central green light is on and the needle stops in the center, your pitch is correct for the note shown.
Tune the instrument using the pitch indicators on the Korg tuner. Pluck a string on the guitar. Tighten the string to raise the pitch if the note shows flat on the screen of the Korg tuner. Lower the tone by loosening the string if the pitch shows sharp. Adjust the pitch of each string to its correct note so the needle stays at the center with the green light on.
Use the sound feature on the Korg CA-30 to play tones for the notes so you can tune by ear. Press the sound button and hold it down for a second. The tones will change from an "A" to a "C." The "C" will continue playing until you press the sound button again, changing it to a "C#." The sound feature plays 12 notes and shows their names on the indicator screen.
Calibrate the Korg tuner. Use the up or down arrows marked "CALIB" to change the pitch of the notes the tuner recognizes or plays in sound mode. The range of the Korg CA-30 tuner is from 410 Hz to 480 Hz, and the arrow keys change the pitch 1 Hz at a time. The default setting of 440 Hz appears when the tuner is turned on, and is used for standard tuning.