The magic of the Masters Tournament, which begins Thursday at the Augusta National Golf Club, is that it has immense appeal both for the golf aficionado and the casual fan with an advanced case of spring fever. It is at once the first leg of golf's modern Grang Slam and the Easter Parade of sports.

Augusta National is a flowering peach of a course -- a scrupulously fair, thinking man's test that glorifies the pure skills and pleasures of the game. It is also a nature lover's dream, ablaze with azaleas, magnolia, dogwood and other fragrant flora native to Georgia.

Spring has arrived in full glory south of the Mason-Dixon line, but in the north, where winter lingers, the tournament is a harbinger of the blessed thaw. This helps account for television ratings that are annually much higher than those for the U.S. Open, British Open and Pga Championships, played in the summer where fewer TV sets are in use.

The time of year is just right for the Masters. Golfers outside the Sun Belt are coming out of hibernation, itching to get their clubs up from the basement. Nongolfers, too, can appreciate a stroll through the wrought iron gates of Augusta National, past the 64 Southern Magnolias that form a leafy canopy over Magnolia Lane, up to the graceful, antebellum-style clubhouse with its immaculately spruced shrubs and flower beds. The aroma of newmown grass and songs of birds chirping their sonates of the season are a tonic after a long winter of discontent.

Even before television and the Masters embraced each other in 1956, sports fans in the still-frosty north savored three-woods among the dogwood through the paeans of Grantland Rice and other sportswriting gods, who annually stopped over in Georgia for a week on their way home from spring training in Florida. Their pastel prose made the Masters appealing and heroic, a heavenly rite of the season.

As a sporting and upper-middle class social institution, the Masters is a living tribute to its late cofounders, Bobby Jones and Clifford Roberts.

Jones, the 24-karat golfing hero of America's golden age of sports, winner of the Grand Slam 51 years ago, was a courtly, Harvard-educated Georgian, revered for his intellect, sportsmanship and love of the game. In collaroration with Scottish architect Alistair Mackenzie, he designed Augusta National in his own image. It has been called "the lengthened shadow of a man."

Roberts, a New York investment banker who idolized Jones, was chairman of the Masters and its driving organizational force from its inception in 1934 until 1976. A crusty, uncompromising perfectionist, he paid strict personal attention to every detail of organization and presentation, making the Masters the standard by which all tournaments were measured. It is a monument to him as well: the lengthened shadow of a curmudgeon.

The Masters always has been image conscious to the point of Old South snobbishness. Commercialism is held to a minimum on Augusta National's 365 acres. Groundsmen in spiffy jumpsuits roam the grounds with pointed sticks, snagging stray bits of litter almost before they touch down. Galleries are limited to manageable size, preferably from the gentry, and are expected to behave like Southern ladies and gentlemen.

In 1967, after enthusiasm for Arnold Palmer threatened to undermine the Masters' essential gentility, Bobby Jones wrote a guide for spectators. The following portion is reprinted every year on pairings sheets distributed to the public:

"In golf, customs of etiquette and decorum are just as important as rules governing play. It is appropriate for spectators to applaud successful strokes in proportion to difficulty, but excessive demonstrations by a player or his partisans are not proper because of the possible effect upon other competitors.

"Most distressing to those who love the game is the applauding or cheering of misplays or misfortunes of a player. Such occurrences have been rare at the Masters, but we must eliminate them entirely if our patrons are to continue to merit their reputation as the most knowledgeable and considerate in the world."

As much as efficiency and understated elegance are a tangible part of the Masters, so is the setting: the rolling, emerald fairways and undulating greens, blending into a backdrop of pines deeply rooted in the red Georgia clay; the flowering trees and shrubs in full blossom; the waters of Rae's Creek, gurgling and occasionally surging under Hogan's Bridge; the ponds of the back nine, dyed blue-green in recent years for benefit of color TV cameras; and the inescapable azaleas, so pink they appear to be blushing from the attention they inspire.

All the holes at Augusta National have botanical names: Yellow Jasmine, Carolina Cherry, Magnolia, Red Bub, Holly, Golden Bell, Firethorn, Chinese Fir and the like. One of the most gorgeous is No. 2, "Pink Dogwood," whose fairway -- a 565-yard dogleg that is the longest on the course by 35 yards -- is bordered by nearly 100 pink dogwoods in full bloom.

Especially scenic is the back nine, beginning with Camellia, a touch par 4 of 485 yards, with a 102-foot vertical drop from the tee to a green that is nestled into a hollow, alongside a grove of ancient pines.

This was the first hole in 1934, but before the field teed off the next April, the order of the front and back nines was reversed. This was one of the few substantial alternations in the course over the years, and an inspired one for both players and spectators. The present back nine is lower in elevation and more sylvan, so it gets the springtime sun later in the day. The current first hold is less demanding than its predecessor. A 400-yard par 4 called Tea Oliver, it is a good appetizer, not too filling, but enough to whet the palate for the delicacies to come.

The modern front nine, dry as a Baptist preacher's parlor on Sunday, is tougher to score on, while the fabled back nine is more spectacular and dramatic, with water coming into play on five holes. The first vision of water is on No. 11, "White Dogwood," a 445-yard par-4 that begins the trio of holes known collectively as "Amen Corner" because so many prayers have been uttered there, so many supplications fulfilled or shattered.

Amen Corner has changed the complexion of many a tournament. It is on the back nine -- where birdies can be had in clusters, but bogeys or worse await those who confuse bravery with recklessness -- that gives the Masters the electric finishes that are its trademark. Augusta National was designed to produce close, palpitating finishes, and almost invariably does. Three-time champion Gary Player has aptly called it "a course built for drama."

Prize money is deemphasized at the Masters.The purse, which is modest by modern standards, is never mentioned. It is the member's green coat that is the champion's most cherished prize.

A sense of history is also a palpable part of the Masters. Landmarks on the course commemorate past champions and celebrated shots, dating back to Gene Sarazen's double eagle on the 15th hole in 1935, enabling him to tie Craig Wood and win the second Masters in a playoff the following afternoon.

Traditions such as asking each first-time winner to donate the club he felt was most instrumental in his triumph to the Augusta National trophy case provide links with the storied past.

The Masters has a mystique that helps turn players into personalities . The robot of the Phoenix Open -- just another fellow in double knits and an Amana visor -- in Augusta becomes a person with fears, aspirations and an anxious wife in the gallery. Contenders for the green jacket become compelling characters in the Easter Parade of sports.