Open C tuning

Open C tuning is an open tuning for guitar. The open-string notes form a C major chord, which is the triad (C,E,G) having the root note C, the major third (C,E), and the perfect fifth (C,G). When the guitar is strummed without fretting even one string, a C-major chord is sounded. By barring all of the strings for one fret (from one to eleven), one finger suffices to fret the other eleven major-chords.

There are several open C tunings.

${ \clef "treble_8" \time 3/4 <c e g c' e' g'>2. <c >4 <e >4 <g >4 <c' >4 <e' >4 <g' >4 <c e g c' e' g'>2. }$

The English guitar uses a repetitive open-C tuning

which is approximately a major-thirds tuning, specifically

${ \clef "treble_8" \time 3/4 <c e aes c' e' aes'>2. <c >4 <e >4 <aes >4 <c' >4 <e' >4 <aes' >4 <c e aes c' e' aes'>2. }$

${ \clef "treble_8" \time 3/4 <c, g, c g c' e'>2. <c, >4 <g, >4 <c >4 <g >4 <c' >4 <e' >4 <c, g, c g c' e'>2. }$

This open C tuning was used by William Ackerman for his "Townsend Shuffle", by John Fahey for his tribute to Mississippi John Hurt, and by Led Zeppelin's Jimmy Page for "Friends". It is also used by Devin Townsend for his work with Strapping Young Lad and The Devin Townsend Project.

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