Les Paul 12-string

The twelve-string guitar is one of the unsung heroes of the recording studio. It might not always take center stage as the primary focus of the song - although when it does that the results can be pretty spectacular - but it can add a really spectacular kind of magic to a track when used at the right moment. Think of the majestic twelve-string interludes of Led Zeppelin's "Stairway To Heaven," or the 'we're about to be hit by a big riff' arpeggios in the beginning of Megadeth's "In My Darkest Hour." Or the jangle hovering about the edges of the chorus of Van Halen's "Poundcake."
If you're not familiar (hey, it can happen), a twelve-string guitar is very much like a six-string guitar, except instead of six individual strings, you have six pairs, most of which are tuned in octaves to each other: the low E, A, D and G strings are each doubled by another string tuned an octave higher, while the B and high E are doubled by strings in the same octave. The octave-higher strings give the guitar a high-end richness that can be almost like a harpsichord or like the biggest damn guitar you ever heard, while the unison strings have a natural chorusing effect of the kind you'll hear from a mandolin or bouzouki. There's something ethereal, almost ghostly about the sound of a twelve-string guitar, whether it's acoustic or electric. It might have something to do with the combined harmonic overtones of all those strings echoing around inside the same hollow guitar body or drifting out of the same speaker.
But there's another way.
What if you could have all of the 'pitch' benefits of a twelve-string guitar, in terms of the beautiful, 'fairies traipsing through the garden' shimmer of the high strings juxtaposed against the more earthbound tones of the conventional strings, yet with finer control over the two? That's one of the benefits of Nashville tuning. As progressive rock auteur and Porcupine Tree founder Steven Wilson put it best recently when I interviewed him: "It’s like the strings that are on a 12-string that are added to the original strings. It’s a six-string but it has this very high, crystalline structure to it because obviously the strings are a very high gauge." When you layer a conventional six-string guitar and a Nashville-tuned guitar together, it sounds like the biggest, most beautiful twelve-string you ever heard, especially once you start messing around with panning in the mixing stage.
Les Paul 6-string

But Nashville tuning isn't just a way of refining the classic twelve-string sound: you can simply play a Nashville-tuned guitar all by itself, with no standard-tuned guitar alongside it, and exploit the particular tonal charms of the tuning in its own context. In fact, Nashville-tuned acoustic guitar is heard at multiple points throughout Wilson's latest solo album The Raven That Refused To Sing (And Other Songs), usually balanced against the other instruments of Wilson's solo band but not necessarily doubling a standard six-stringer. "I found that incredibly inspiring, and you can hear the inspiration of that guitar on a song like "Watchmaker"," Wilson said, adding that not only was the Nashville-tuned guitar an important part of his guitar arsenal for Raven, but it was exerting a similar influence over its follow-up.
One particularly fun Nashville tuning trick is to record standard and Nashville guitars panned dead center for strummed chords, then split them off into hard left and right for arpeggios. This can be a very beautiful sound when you're rocking an acoustic, but it can really come alive when you're using clean or slightly overdriven electric guitars with a little compression. And there's no reason you can't layer a standard-tuned electric and a Nashville-tuned acoustic, or vice versa. In fact, a sparkly acoustic Nashville-tuned guitar part placed over a chunky distorted rock riff can occupy a similar chunk of musical real estate to a keyboard part. Or consider adding effects to just one of your two guitars. A bone-dry Nashville-tuned guitar can add clarity and definition to a heavily ‘reverbed’ standard-tuned one. Or delay and modulation effects can provide some air and shimmer to a hard-hitting riff that might otherwise feel a little claustrophobic.
Of course, as with any slightly left-of-center technique, there's always something new you can do with it, and it's totally dictated by the needs of the song. If you've experimented with Nashville tuning and found some interesting new uses for it, we'd love to hear your ideas.