(This is edited from an answer I posted to KeyMinor, a music Q&A site. They need more users!)
A lot of recordings end up slightly higher/lower than standardized pitch (I always called this “in the cracks” but don’t google it!), and this is the quickest way I’ve found to tune a guitar to them. This method seems simplistic but has several advantages going for it:
- All strings are tuned to the same reference pitch, so there’s no accumulation of error as you move from string to string (and you can tune any of the top 5 in any order).
- The higher the frequency, the easier it is to notice the beat when two identical notes differ slightly in pitch. Matching high pitches yields lower error.
- All pitch matching is done with notes in the same octave; this also helps you notice the beat
Here it is.
- Get string 1 (high E note) perfectly in tune with the recording so that you can play along with the song at various points on the string. Ideally the song will be in a key containing E because getting open E perfect is essential to this method. Check the 12th and 7th fret harmonics, too. If either sounds off, you know you’re not quite done.
- Stop the recording and tune string 2 until its 5th fret matches string 1 open.
- Tune string 3 until its 9th fret matches string 1 open.
- Start the recording and play along using the strings you’ve tuned. If it’s off, return to step 1.
- Stop the recording and tune string 4 until its 14th fret matches string 1 open. Get it as close as you can and check the caveats below.
- Tune string 5 until its 7th fret harmonic matches string 1 open.
- Tune string 6 until its 5th fret harmonic matches string 1 open.
- Your strings must be well-settled/worn in. You especially don’t want the high E to change pitch at all during tuning.
- If your D string has intonation problems, the 14th fret may not be in-tune with the lower frets. You may have to tune the D string using some other method at the end. You could, of course, have similar problems with the G and B strings if your intonation is really messed up.
- As you’re tuning, often you’ll get to a point where it seems perfect. Give it a little nudge more and often you’ll hear the two notes sink together, becoming one—that’s where you really want it.