Tuning a guitar is an essential part of playing any style of music, and the same is true for playing a Hawaiian Slack Key guitar. But tuning the guitar is only part of the picture.
There are a myriad of guitar styles played with open tunings that are not Slack Key or Hawaiian Slack Key.
The Slack Key is a style of playing the guitar chosen with the fingers. Some musicians, such as Leddy Kaapana, use just two fingers, while others, such as Keola Beamer, use all four fingers of their hand.Most play with just their fingers, but Sean Robbins likes to use finger picks. According to Robbins, one thing that hasn't happened yet is someone touching the slack key with a flat pick. The unique sound of Slack Key comes from techniques such as “hammering-on” and “pulling-off” which imitate the Tyrolean and falsettes common in Hawaiian singing. Also common are harmonics (“ringing”), which are produced by lightly touching the strings at certain points on the fretboard, and slides in which one or two high-pitched notes are played and then slid (usually upward) to make another note sound.
All of these techniques enhance the feeling of aloha, joy or longing that is expressed, sometimes all in the same song. The tradition of the loose key received an important boost during the reign of King David Kalākaua, responsible for the Hawaiian cultural revival in the 1880s and 1890s. George Kanahele worked hard to publicize his publications, his music classes and his sponsorship of concerts, including the emblematic 1972 Slack Key concert. My first kumu (teacher) was Bobby Moderow Jr., a protégé of Nānākuli's principal Slack Key teacher, Raymond Kaleoalohapoinaʻoleohelemanu Kāne.
When I played my favorite Scruggs songs, the result was a lot like the way I played the Hawaiian slack key. The technique can be seen in the song Kaulaʻili from Susan Friedman's film Kī Hōʻalu, That's Slack Key Guitar and in Eddie Kamae's great movie The Hawaiian Way. From the 1960s, and especially throughout the 1990s to the present day, the Hawaiian loose-fitting guitar has evolved to become a highly developed instrumental art form, both solo and in groups. According to slack key legend Cyril Pahinui, the slack key is essentially a Hawaiian term for what is more commonly known as open tuning.
The rise of ukulele music has now spread to pop, country and classical music, often with a loose-fitting guitar or bass for the tempo. Without this, loose tonality becomes a mere technique, something that veterans would never approve or recognize as Kī Hō'alu. Many Hawaiian songs and loose-toned guitar pieces reflect themes such as stories from the past and present and people's lives. These four, together with Sonny Chillingworth, recorded in the 1950s, 1960s and 1970s (Gabby Pahinui began recording in the 1940s) and influenced all the younger guitarists.
As a child growing up in O'ahu, I had the immense fortune to learn from some of the leading Hawaiian guitar players Slack Key. The combination of these three parts played simultaneously on a single guitar, with loose or “open” tuning, is what constitutes the basic guitar approach known as Hawaiian Slack Key. The Scruggs two-finger style doesn't have to produce bluegrass, so if you're saying that the Slack Key style doesn't have to produce Hawaiian music, I think I have it. There are now more loose key guitar recordings in Hawaii, on the mainland and in other countries, and several guitarists are touring more frequently outside of Hawaii.