Open C tuning is an open tuning for guitar. The open-stringnotes form a C majorchord, 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 any strings, 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.
Another open C tuning uses the harmonic sequence (overtones) of the note C. When an open-note C-string is struck, its harmonic sequence begins with the notes (C,C,G,C,E,G,B♭,C). The root note is associated with a sequence of intervals, beginning with the unison interval (C,C), the octave interval (C,C), the perfect fifth (C,G), the perfect fourth (G,C), the major third (C,E), and the minor third (E,G); in particular, this sequence of intervals contains the thirds of the C-major chord {(C,E),(E,G)}.[9]
C-minor open chord: Cross-note tuning
Flattening this open tuning's open-note E to E♭ changes the open chord from C-major to C-minor, so producing the cross-note tuning
C-C--G-C-E♭-G
which enables one-finger minor chords. Like other cross-note tunings, it also allows major chords to be fretted with one adjacent finger.[10]
NST is used in Guitar Craft (a school of guitar playing founded by King Crimson's Robert Fripp). The open-C overtones tuning has the same range as NST, which can use extreme strings (.011 and .059 inches).[12]
C-C-G-C-E-C
C-C-G-C-E-C
Using a high C rather than the high G of the overtone series, this open C tuning was used by Mick Ralphs for the songs "Can't Get Enough" and "Movin' On" on Bad Company's debut album. Ralphs said, "It needs the open C to have that ring," and "it never really sounds right in standard tuning".[13]
Notes
^Annala, Hannu; Mätlik, Heiki (2007). "Composers for other plucked instruments: Rudolf Straube (1717–1785)". Handbook of guitar and lute composers (Translated by Katarina Backman ed.). Mel Bay. p. 30. ISBN0786658444.
^Page's "Friends" tuning is called an C6 chord (C-A-C-G-C-E) in Page 92: Welch, Chris (1998). Led Zeppelin: Dazed and confused: The stories behind every song. ISBN1-56025-818-7.
^Guitar Tunings Database (2013). "CCGCEG Guitar Tuner". CCGCEG: Open C via harmonic overtones. Archived from the original on 10 March 2013. Retrieved 20 February 2013.
Sethares, Bill (2009) [2001]. "Open tunings". Alternate tuning guide(PDF). Madison, Wisconsin: University of Wisconsin; Department of Electrical Engineering.