Editing Eight-string guitar (section)

===Semi-acoustic guitar (hollow-body guitar)===
{{See also|Semi-acoustic guitar|Archtop guitar}}

Seeking a [[guitar tuning]] that would facilitate jazz [[improvisation]], [[Ralph&nbsp;Patt]] invented [[major-thirds tuning]] in 1963.<ref name="Griewank1" >{{harvtxt|Griewank|2010|p=1}}</ref><ref name="Kirkeby">{{cite web|first=Ole|last=Kirkeby|date=1 March 2012|title=Major&nbsp;thirds tuning|url=http://v3p0.m3guitar.com/|publisher=m3guitar.com|archive-url=https://web.archive.org/web/20150411064851/http://v3p0.m3guitar.com/|archive-date=11 April 2015|id=cited by {{harvtxt|Sethares|2011}} and {{harv|Griewank|2010|p=1}}}}</ref><ref name="Patt">{{cite web|url=http://www.ralphpatt.com/Tune.html|first=Ralph|last=Patt|publisher=ralphpatt.com|work=Ralph&nbsp;Patt's jazz web page|title=The major&nbsp;3rd tuning|date=14 April 2008|access-date=10 June 2012|id=cited by {{harvtxt|Sethares|2011}} and {{harvtxt|Griewank|2010|p=1}}}}</ref> Patt's tuning is a [[regular tunings|regular tuning]], in the sense that all of the [[interval (music)|interval]]s between its successive [[open string (music)|open string]]s are [[major third]]s; in contrast, [[standard guitar tuning]] has one major-third amid four [[perfect fourth|fourth]]s.<ref name="Sethares2001">{{harvtxt|Sethares|2001}}</ref>

[[Seven-string guitar]]s are needed for major-thirds tuning to have the E-e' range of the standard tuning.<ref name="Sethares2001"/><ref name="Peterson37">{{cite journal|title=Tuning in thirds: A new approach to playing leads to a new kind of guitar |first=Jonathon |last=Peterson |location=Tacoma WA|url=http://www.luth.org/backissues/al69-72/al72.htm |journal=American Lutherie: The Quarterly Journal of the Guild of American Luthiers |publisher=The Guild of American Luthiers |issn=1041-7176 |volume=72 |date=Winter 2002 |access-date=9 October 2012 |pages=36–43 ] |url-status=dead |archive-url=https://web.archive.org/web/20111021185726/http://www.luth.org/backissues/al69-72/al72.htm |archive-date=21 October 2011 }}{{rp|37}}</ref> Having an eight-string instrument allowed Patt's guitar to have G{{music|sharp}} ([[enharmonic equivalency|equivalently]] A{{music|flat}}) as its [[open note]].<ref name="Peterson37"/> Patt purchased six-string [[archtop guitar|archtop]] [[semi-acoustic guitar|hollow-body guitar]]s that were then modified by luthiers to have wider necks, wider pickups, and eight strings. Patt's Gibson ES-150 was modified by Vincent "Jimmy" DiSerio c. 1965.<ref name="Patt"/><ref name="Peterson37"/> Luthier [[Saul Koll]] modified a sequence of guitars: a 1938 Gibson Cromwell, a Sears Silvertone, a c. 1922 Mango archtop, a 1951 Gibson L-50, and a 1932 Epiphone Broadway; for Koll's modifications, custom pick-ups accommodated Patt's wide necks and high G{{music|sharp}} ([[enharmonic equivalency|equivalently]] A{{music|flat}});<ref name="Peterson37"/> custom pick-ups were manufactured by [[Seymour&nbsp;Duncan]]<ref name="Peterson37"/> and by Bill&nbsp;Lawrence.<ref name="Patt"/> Roy Connors, former member of the 1960s folk singing group, [[The Highwaymen (folk band)|The Highwaymen]], reconfigured a Martin O-28 six-string guitar to an eight-string of his own design and received a U.S. Patent on it (#3269247).