The music did not receive a mainland audience during the Hawaiian music craze of the early 20th century, during which Hawaiian music came to be identified outside of Islands with the steel guitar and the ukulele. Slack key remained private and family entertainment, and it was not even recorded until 1946-47, when Gabby Pahinui cut a series of records that brought the tradition into public view. During the 1960s and particularly during the Hawaiian Cultural Renaissance of the 1970s, slack key experienced a surge in popularity and came to be seen as one of the most genuine expressions of Hawaiian spirit, principally thanks to Gabby Pahinui, Leonard Kwan, Sonny Chillingworth, Raymond Kāne, and the more modern styles of younger-generation players such as Keola Beamer, his brother Kapono Beamer, Peter Moon, and Haunani Apoliona.
Many currently prominent Hawaii-based players got their starts during the Cultural Renaissance years: Cindy Combs, Ledward Kaapana, George Kahumoku, Jr., his brother Moses Kahumoku, Dennis Kamakahi, Ozzie Kotani, three Pahinui brothers ([Bla, Cyril, and Martin), the Emerson Brothers and Owana Salazar. These artists, and slack key in general, have become well-known outside of Hawaii largely through George Winston's Dancing Cat Records record label, which has most often showcased the music in solo settings.
One indication of slack key's increasing visibility beyond the Islands is that when The Recording Academy instituted a GRAMMY Award for Best Hawaiian Music Album, the first three winners were slack key collections produced in Hawaii: Slack Key Guitar, Volume 2 in 2005, Masters of Hawaiian Slack Key Guitar, Volume 1 in 2006, and Legends of Hawaiian Slack Key Guitar—Live from Maui. Players from outside Hawaii have also taken up the tradition, for example, Chet Atkins (who included slack key pieces on two of his albums), Yuki Yamauchi (a student of Ray Kane's and advocate of Hawaiian music in Japan), and Canadian Jim "Kimo" West (perhaps better known as guitarist with "Weird Al" Yankovic).
Nearly all slack key requires retuning the guitar strings from the standard EADGBE, and this usually (but not always) means lowering or "slacking" several strings. The result will most often be a major chord, although it can also be a major-seventh chord, a sixth, or (rarely) a minor. (There are examples of slack key played in standard tuning, but the overwhelming majority of recorded examples use altered tunings.) The most common slack key tuning, called "taro patch," makes a G major chord. Starting from the standard EADGBE, the high and low E strings are lowered or "slacked" to D and the fifth string from A down to G, so the notes become DGDGBD. As the chart below shows, there are also major-chord tunings based on C, F, and D.
Another important group of tunings, based on major-seventh chords, is called wahine. G wahine, for example, starts with taro patch and lowers the third string from G to F#, making DGDF#BD. Wahine tunings have their own characteristic vamps (as in, for example, Raymond Kāne's "Punahele" or Gabby Pahinui's 1946 "Hula Medley") and require fretting one or two strings to form a major chord. A third significant group is Mauna Loa tunings, in which the highest pair of strings are a fifth apart: Gabby Pahinui often played in C Mauna Loa, CGEGAE.
There are many slack key tunings—George Winston has identified fifty—with some tunings only commonly used for a single song, or by particular players. Mike McClellan and George Winston have developed schemes that organize the tunings by key and type. The chart below follows their categories and naming conventions.
|Common Slack Key Tunings||Notes Used|
|G Major or Taro Patch||D G D G B D|
|G Wahine||D G D F# B D|
|D Wahine||D A D F# A C#|
|Open D||D A D F# A D|
|C Major or Atta's C||C G E G C E|
|Mauna Loa||C G E G A E|
|C Wahine or Leonard's C||C G D G B D|
|C 6||C G C G A E|
|Old Mauna Loa||C G C G A D|
|Open C||C G C E G C|
|F Wahine||C F C G C E|
|Open F||C F C F A C|
|Double Slack F||C F C E A C|