PHOTO: Mike Duffy
If you don't have access to a digital tuner, this will help.
By Jeff Owens
Absent an electronic tuner or the tuner you may have on your phone (here's one we like if you're in need) you can always use harmonics to tune your guitar to itself.
What are harmonics?
Harmonics are overtones set at fixed intervals that work in "harmony" with a fundamental tone. Picture them as complemtary soundwaves to the waveform produced by a root tone.
To make a harmonic tone place your finger gently on the low E string directly above the fifth fret. Don't press down. The string should only be touching your finger and should hover over the fretwire.
Strike the string and you should hear a sustained, ringing tone: That's the fifth-fret harmonic of the E string. Do the same on the seventh fret of the A string and you'll hear the seventh-fret harmonic of A.
Sounding the fifth-fret harmonic of a string and matching the seventh-fret harmonic of the string directly above to it is one of the easiest and most reliable ways to tune a guitar to itself.
So if you sound the fifth-fret harmonic on your low E string, you can tune the A string by sounding its seventh-fret harmonic while the fifth-fret E-string harmonic is still ringing. The notes should be identical.
If the two strings are even slightly out of tune with each other, you’ll notice an audible oscillation or pulsating effect while both notes are ringing together. If so just adjust the A string until the oscillation goes away and both harmonics sound exactly the same.