THEATER : After Seeing ‘Show Boat’ as Boy, He Signed On for the Duration : Theater: Miles Kreuger found magic in the show and has become a part of its continuing life and memorabilia. He will lecture as a prelude to the Opera Pacific production.

Miles Kreuger was 11, already a seasoned theatergoer of seven years, when he got his first look at “Show Boat” in its 1946 Broadway revival.

“I found myself utterly mesmerized by it,” Kreuger, now 56, recalls. “Not just because of the beauty of the score--I had seen many other shows that had beautiful scores--but there was something almost mystical in its effect upon me. . . . I couldn’t get it out of my mind.”

That’s putting it mildly.

Kreuger, founder and president of the Los Angeles-based Institute of the American Musical, is not only the expert on the Jerome Kern-Oscar Hammerstein II musical but has come to play a major role in the continuing life of the ground-breaking 1927 show.

The historian, who will lecture on “Show Boat” tonight as a prelude to the upcoming Opera Pacific production in Costa Mesa, owns the only surviving original script of the musical--a personal gift from Hammerstein himself. The original 1927 orchestrations were believed lost, until Kreuger discovered the conductor’s score in a New York warehouse in 1978.

Kreuger led a successful search for a complete copy of the 1929 silent-film version. He wrote a book on the musical in all its transmutations, released to coincide with its 50th anniversary in 1977 and now due for reissue. He got a Grammy nomination for his liner notes to the 1989 Angel Records reconstruction of the show and did the research and narration for the Criterion laser disc release of the 1936 film version.

For Kreuger, it has all been a labor of love.

“These aren’t just characters in literature or in theater. You come to know these people, and years after you’ve seen ‘Show Boat,’ you think of Magnolia and all these people as your friends. You remember them,” Kreuger said.

His feelings, he insists, are not unusual: “It’s not just indigenous to me. Other people have told me they feel the same. They saw ‘Show Boat’ when they were 10 years old and they can’t forget it; they can’t get it out of their system. There’s something mesmerizing about that work.”

Based on Edna Ferber’s 1926 novel, “Show Boat” follows a performing troupe on the Mississippi, beginning in 1890. The musical opened on Broadway (after the usual out-of-town tuning) on Dec. 27, 1927, and was, Kreuger says, a turning point in the maturation of the American musical.

“Show Boat was the first of a great many things,” he says. “It was the first musical to treat certain themes very seriously, themes that weren’t treated very often in non-musicals, like miscegenation.” It was also among the first shows to feature an interracial cast performing on stage together.

Then, of course, there is the score--featuring such tunes as “Ol’ Man River,” “Bill” and “Can’t Help Lovin’ Dat Man”--and the show’s historical sweep: “ ‘Show Boat’ deals with a whole epoch of Americana in the South, and all of the changing values as well,” Kreuger said.

Aside from a few operettas such as “The Desert Song,” which Kreuger says are “clearly period pieces,” “Show Boat” is the only musical of the ‘20s that is still regularly performed. “ ‘Show Boat’ does still retain a sense of theatrical urgency and freshness,” he said.

Like the musical with which he has become identified, Kreuger himself is something of an original. During a life in various aspects of the theater, he began collecting treasures great and small, and in 1972 founded his institute in New York.

Lured by a Rockefeller Foundation grant, he moved the collection West in 1978, losing some precious items in a truck accident along the way. He and the remainder of his collection settled in a Los Angeles duplex, which the institute purchased in 1985 and which he and his two dogs continue to share with a voluminous collection of recordings, sheet music, scripts, scores, still photographs, signed letters and playbills.

The collection is marked by some unusual gems, which Kreuger has amassed largely through his personal friendships with a range of figures from American theater, along with an uncanny gift for serendipitous finds. There’s Cole Porter’s personal script for “Anything Goes,” Harold Arlen’s home movie collection, and a variety of memorabilia from stage stars and behind-the-scenes figures.

One of his prized possessions is a set of silent home movies taken by a Florida resident, the late Ray Knight, who for years sneaked his camera into Broadway musicals from the ‘30s on, producing in many cases a one-of-a-kind document.

Kreuger’s dazzling collection is matched by his encyclopedic memory. He is an animated, engrossing storyteller whose tales are marked by exacting detail.

On his friendship with Hammerstein:

“I met him in 1955 and we talked about ‘Show Boat’ all the time until he died in 1960. And on his last day alive in New York City, which was Wednesday, Aug. 3, 1960, he invited me to his home and I spent the whole day with him at 10 E. 63rd St., and at the end of the day, around 5 in the afternoon, the time had come for his chauffeur to take him and his wife Dorothy to Bucks County, Pa., where they had a house, and where he died 20 days later.

“As we got up from the sitting room where we were spending the afternoon, he walked to a book cabinet, withdrew something, looked at it very solemnly and said, ‘I think this ought to belong to you. . . . It’s my personal script of ‘Show Boat’ from 1927. It’s the only copy in the world and I think you ought to have it.”

And on his discovery of the “Show Boat” score, on the last Saturday before he left New York for Los Angeles in 1978:

“I got permission to go to the Rogers and Hammerstein warehouse with somebody from their office and with Robert Russell Bennett himself (the original orchestrator), because I was determined I would not leave New York without locating the original orchestrations. It was like a calling.”

The warehouse was meticulously catalogued--”They were really humoring a madman”--but Kreuger was determined anyway. He walked in “as if I had a divining rod and was being guided through the maze of corridors. . . . I suddenly stopped and looked up at the top shelf, that was far beyond my reach (and) there were three boxes up there that were different colors than all the others. I said, ‘They’re not labeled. That’s where “Show Boat” is.’ ”

Someone retrieved the first box and brought it to Bennett. “He opened the box and screamed, ‘Eureka!’ ” Kreuger said. It was the 1927 conductor’s score, with a reduction of all the orchestral parts.

“For the first time, as of that last April Saturday in 1978,” Kreuger said, “it was possible to revive ‘Show Boat’ authentically.”

Miles Kreuger will speak about “Show Boat” (to be produced Friday through July 22 by Opera Pacific at the Orange County Performing Arts Center) at 7:30 p.m. at the Westin South Coast Plaza hotel, 666 Anton Blvd., Costa Mesa. Admission: $15. Information: (714) 546-7372.