conventional in standard tuning: This open-position C7 chord is termed a second-inversion C7 drop 2 chord (C, G, B, E), because the second-highest note (C) in the second-inversion C7 chord (G, B, C, E) is lowered by an octave. Disadvantages While major thirds tuning confers the numerous advantages detailed above, it also introduces certain disadvantages, as compared to the instrument's standard tuning: M3 tuning decreases the overall range of the guitar (this is why some players eventually resorted to 7- and 8- string instruments, to regain that lost range) M3 simplifies the voicing of chords in close harmony, but it makes certain common voicings in open harmony more difficult, or even impossible M3 facilitates moving 3- and 4-note chords up or down an octave, but it makes the fingerings for 5- and 6-note multi-octave chords more complex and awkward. History Major-thirds tuning was introduced in 1964 by jazz guitarist Ralph Patt. He was studying with Gunther Schuller, whose twelve-tone technique was invented for atonal composition by his teacher, Arnold Schoenberg. Patt was also inspired by the free jazz of Ornette Coleman and John Coltrane. Seeking a guitar tuning that would facilitate improvisation using twelve tones, he introduced major-thirds tuning by 1964, perhaps in 1963. To achieve the E−E open-string range of standard (Spanish) tuning, Patt started using seven-string guitars in 1963, before settling on eight-string guitars with high G (equivalently A) as their highest open-notes. Patt used major-thirds tuning during all of his work as a session musician after 1965 in New York. Patt developed a webpage with extensive information about major-thirds tuning. See also Minor-thirds tuning Repetitive open-tunings approximate M3 tunings: Non-Spanish classical guitars: English: Its open-C tuning C–E–G–C–E–G approximates C–E–G–C–E–G Russian: Its 7-string open-G tuning G–B–D–G–B–D–G approximates G–B–D–G–B–D–G Other open tunings Open A tuning: E–A–C–E–A–C approximates F–A–C–F–A–C Open B tuning: F–B–D–F–B–D approximates G–B–D–G–B–D Open C tuning: C–E–G–C–E–G approximates C–E–G–C–E–G Open D tuning: D–F–A–D–F–A approximates D–F–A–D–F–A Open E tuning: E–G–B–E–G–B approximates E–G–C–E–G–C Open F tuning: F–A–C–F–A–C approximates F–A–C–F–A–C Open G tuning: G–B–D–G–B–D approximates G–B–D–G–B–D References Footnotes Citations Bibliography Further reading External links Professors Andreas Griewank and William Sethares each recommend discussions of major-thirds tuning by two jazz-guitarists, and : Ole Kirkeby for 6- and 7-string guitars: Charts of intervals, major, minor, and dominant chords; recommended gauges for strings. Ralph Patt for 6-, 7-, and 8-string guitars: Charts of scales, chords, and chord-progressions; string gauges. Three other jazz-guitar websites: Regular