To the people of Hawai'i and those familiar with the culture of the Islands, the word "aloha" is not simply a greeting or a goodbye, but a word with a broader meaning of love or respect.

In many ways, aloha is a feeling or spirit. It's also what Hawai'i slack-key guitar phenom Makana believes is at the heart of his musical genre's tradition.

"It's not about how to impress you, but what's beautiful — the feeling of aloha," he said.

Without aloha, the style of Hawaiian slack-key guitar playing or ki ho'alu, is merely a collection of techniques. The 31-year-old musician from Honolulu explained during a recent interview that slack-key's "voicings make it cultural, and the approach makes it universal."

Makana, which means "gift freely given," began life as Matt Swalinkavich on the island of O'ahu. At age 11, he began studying slack-key guitar with Maunalua founding member Bobby Moderow Jr. Moderow taught the young Makana mainly in the style of slack-key kahuna Raymond Kane. Moderow had been a student of Kane.

At 13, Makana, who by this time had appeared on a TV show called "SuperKids Hawaii," went to a slack-key festival to watch another of the genre's icons perform — Sonny Chillingworth.

As Makana tells it, upon meeting Chillingworth, the guitar legend said to him, "Young man, I've been looking for you."

Not long after this portentous meeting, Makana began a period of study with his "Uncle Sonny," as he reverentially refers to Chillingworth, a relationship that continued until the elder guitarist's death in 1994.

Makana's first original composition, written at age 15, is a song dedicated to Chillingworth called "Song for Sonny" from the album "Ki ho'alu Journey of Hawaiian Slack Key." Performed during a concert last month at Washington's National Geographic Society, the song is a plaintive yet sophisticated reminiscence that showcases Makana's dulcet tenor and includes both English and Hawaiian lyrics.

The National Geographic show was videotaped for a series called "Geo Sessions" for the society's burgeoning musical television channel, which airs only in Europe but will be showcased for a time this summer on North America's National Geographic Channel.

In a purely technical sense, slack-key guitar is defined by the loosening of the guitar strings to produce alternate tunings. The standard tuning of a six-string guitar in the Spanish tradition is: from the top, or lowest-sounding string, the musical notes E-A-D-G-B-E. The vast majority of guitar-oriented music, from blues to rock, jazz to country, is played in this tuning.

In slack-key, the six strings are often tuned to notes which, when strummed unfretted, that is, with no fingering on the fret board, produce a chord. This is generally referred to as open tuning. A common slack-key open tuning is "major" tuning, where all the strings are tuned to produce a major chord, like G major, D-G-D-G-B-D. Within this overriding sonority, the guitarist is free to fret individual notes, with just one or two fingers, rather than using less nimble chord shapes that require more fingers.

A guitar string plucked unfretted will have more of a reverberating drone quality and can provide an underlying sound that supports the melody picked out on the higher strings.

Slack-key guitarists can employ a rhythmic bass line by picking the low strings with the thumb in alternating patterns. Here's where the dexterity made possible by the open tuning is most significant. While the guitarist is free to wander up and down the fret board playing individual notes, he must do this at the same time the thumb is providing the bass line. The overall effect is the sound of not one, but multiple guitars being played.

Makana traces this integrated style of playing to what he refers to as his Hawaiian musical ancestors' "efficiency."

Guitars were first brought to the Hawaiian islands by cattlemen of Mexican or Spanish heritage. These "vaqueros" were a form of early migrant workers with few possessions. Their guitars may have been their only musical instruments, and so out of necessity, the guitarists became, in effect, the whole band.

Makana says what makes slack-key special is that it's "simulating a symphony." He continues his account of the experience between the performer and his audience in slack key by emphasizing that the "listener's mind is the second instrument."

At a show at the Maui Arts & Cultural Center earlier this year, Makana began his first set with Yaz's "Only You." His version strips away the layers of electronica that the English pop duet were famous for in the 1980s, and reduces it to the raw power of his single acoustic guitar.

"How do I do all this on one guitar?" Makana asks. "First, I find a comfortable key, incorporate a pedaling bass, with a flicking faux rhythm on the high strings, with a melody and then a sung melody."

For Makana, the refinement of all these disparate elements is the essence of his brand of slack-key.

"The art form," he says, "is distilling something massive — taking something indigenous, ethnic, cultural, and boil it down. It's all psychology. You gotta make a statement."