Looking Back--His Way : Pop music review: Reprise Records’ new 20-disc set chronicles the high and low points of Frank Sinatra’s unparalleled singing career.

Reprise Records’ extraordinary new “Frank Sinatra: The Complete Reprise Studio Recordings” is certainly not your usual holiday stocking stuffer.

The 20-disc box set, which will be released Tuesday, is a major commitment of time and money. It takes 24 hours nonstop to listen to the entire collection, and the suggested retail price is a whopping $499.

Overflowing with more than 450 songs, the set is the most lavish--and revealing--of a series of albums being released in connection with Sinatra’s 80th birthday Dec. 12.

The Reprise set chronicles the years from 1960 to 1988, including the three “golden” musical periods of the most acclaimed singer ever in pop music--a consummate balladeer, saloon singer and big-band vocalist who dazzled us with the sophistication of his phrasing without sacrificing the intimacy and warmth that gave his music an Everyman quality. It’s the cream of the current crop of Frank-mania.

Already in the stores from Capitol Records: “Sinatra 80th: All the Best,” a two-disc set of his celebrated ‘50s recordings, and “Sinatra 80th: Live in Concert,” a single disc of live recordings from the late ‘80s that includes an over-the-top duet with Luciano Pavarotti on “My Way.” Also available: “Frank Sinatra: The Best of the Columbia Years 1943-1952,” a four-disc package drawn from his first golden period.

The birthday celebration continues Sunday night at the Shrine Auditorium when a host of performers, from Ray Charles and Bob Dylan to Tony Bennett and Bruce Springsteen, toast him in a benefit concert that will be broadcast Dec. 14 on ABC-TV.

Because the Reprise package delivers all the studio recordings of his most interesting period (if not always the most satisfying, in terms of voice and material), it is the most fascinating of the works.

We get to look behind the swagger and genius to hear Sinatra at his most relaxed (joyfully redoing signature songs from his Capitol and Columbia years), at his most adventurous (reaching out to new material and new arrangers) and at his most futile (trying, usually in vain, to connect with contemporary pop-rock songs).

The Reprise set, which will be limited to 20,000 copies, offers a hardcover booklet filled with essays and recording information, but the best way to appreciate the factors at work during the Reprise years is to read Will Friedwald’s “Sinatra! The Song Is You” (Scribner, $30).

Although Friedwald is far too closed-minded when it comes to contemporary pop music, his book is a stimulating guide to Sinatra the artist. The book is especially helpful in putting the music in the context of Sinatra the businessman.

The chief reason Sinatra left Capitol Records, the author notes, is that he wanted the respect and rewards of owning a label. Sinatra is quoted as once pointing to the Capitol Tower and declaring to a cohort, “I helped build that. Now, let’s build one of my own.”

Sinatra’s joy is evident in the early sessions for his label. Even the playful title of his first Reprise album--”Ring-A-Ding Ding!”--seemed to mirror his confidence and enthusiasm. Using songs by the likes of Cole Porter, the Gershwins and Irving Berlin, Sinatra recorded the album in December, 1960, and it jumped into the national Top 10.

Rather than stick with the excellent core of arrangers that had served him so well at Capitol, Sinatra followed the advice of his pop hero, Bing Crosby, and worked with a variety of arrangers, trying to bring added flavor and imagination to his music. Among those joining Capitol-era greats Nelson Riddle, Billy May and Gordon Jenkins were Don Costa, Johnny Mandel, Sy Oliver, Neal Hefti, Eumir Deodato and Quincy Jones.

Excited, Sinatra moved in a variety of directions, recording with one favorite band (Count Basie’s) and saluting another one (Tommy Dorsey’s).

While these early Reprise albums maintained his adult fan base, they didn’t put him back into the contemporary mainstream. So he set aside the classic tunes and went into the studio in February, 1962, with Hefti in hopes of jumping on the “twist” dance craze.

The song “Everybody’s Twistin’ ” tried to mix Sinatra’s patented sophistication with the most mindless novelty, and it was a disaster. The single only spent two weeks on the pop charts, peaking at No. 75. Friedwald doesn’t even refer to it, and Sinatra probably only remembers it in his worst dreams.

Wisely, he went back to making music his way--with strings here, with swinging brass there. It wasn’t until he hooked up with record producer (and former rock singer) Jimmy Bowen in the mid-’60s that Sinatra made another concentrated run at the youth market.

Bowen and arranger Ernie Freeman started to modernize Sinatra’s sound with “Softly, As I Leave You.” The ballad made it to No. 27 on the charts in 1964 and opened the door for Sinatra to work again with Freeman, who had a background in R&B; and had scored an instrumental hit in the ‘50s with “Raunchy.”

The breakthrough was “Strangers in the Night,” a contemporary ballad that reached No. 1 in the summer of 1966. The record apparently gave Freeman the confidence to really push Sinatra on “That’s Life,” an out-and-out soul scorcher. While often scoffed at by Sinatrapurists, the single casts him in the commanding role of soul singer as he expresses his own career and personal trials with much of his famed “My Way” independence.

Surprisingly, Sinatra found the Dean Kay/Kelly Gordon song himself and first had Riddle do an arrangement, only then turning to Freeman for a more aggressive sound. Soul greats Aretha Franklin and James Brown later recorded the song, but neither version matched Sinatra’s punch.

The record’s success encouraged him to work with more contemporary songs, including tunes by such writers as Joni Mitchell, Paul Simon, Jimmy Webb, Neil Diamond and Lennon-McCartney. He connected on a few of them artistically, but he rarely seemed comfortable with the new crop of writers.

The low spot was a version of John Hartford’s “Gentle on My Mind,” a tale of youthful wanderlust, in which this 50-ish singer tries to convince us he would really stash his sleeping bag behind a loved one’s couch.

As unconvincing as Sinatra often was on even appropriate pop-rock material, he was still able to do marvelous work well into the September of his own years, teaming with Duke Ellington and Antonio Carlos Jobim on more mature projects.

Despite the inevitable vocal deterioration over the years and such baffling missteps as an entire album of Rod McKuen songs, Sinatra--throughout the Reprise years--was able to touch and delight us with an unexpected nuance or twist of phrase. Through this long musical journey, you know you’re in the presence of a master. Hearing some of his less than perfect moments only makes this often enigmatic figure all the more human.