Major thirds tuning also facilitate advanced guitarists' improvisation, precisely the aim of jazz guitarist Ralph Patt when he began popularizing major-thirds tuning between 1963 and 1964. In standard tuning, the successive open-strings mix two types of intervals, four perfect-fourths and the major third between the G and B strings: Only major thirds occur as open-string intervals for major-thirds tuning, which is also called ""major-third" tuning", ""all-thirds" tuning", and ""M3" tuning". A popular M3 tuning has the open strings in which the low G is a major third above the low E of standard tuning. Consequently, a seventh string for the low E is
Rule of thirds (diving) Rule of thirds (diving) In scuba diving, the rule of thirds is a rule of thumb used by divers to plan dives so they have enough breathing gas remaining in their diving cylinder at the end of the dive to be able to complete the dive safely. This rule generally only applies to diving in overhead environments, such as caves and wrecks, where a direct ascent to the surface is impossible and the divers must return the way they came. For divers following the rule, one third of the gas supply is planned for the outward journey, one third is