For John McGlinn it all began with Jerome Kern.

"It was his 100th birthday and I persuaded Cy Rosen, who was the head of Carnegie Hall, to let me do concert versions of three of the Princess Theatre shows. The Princess Theatre was a small theater, around 300 seats, and Carnegie Recital Hall was around 300 seats. So he said yes, and we did concert performances of `Oh, Boy!' `Oh, Lady! Lady!!' and `Zip! Goes a Million.' It was my first time conducting in New York, and I don't think I've ever been more terrified in my life than the opening night of `Oh, Boy!' Little did I know John Rockwell (of the New York Times) was in the audience covering the concert."That was in 1985 and the result, by McGlinn's own admission, was "a review that literally changed my life."

First the folks at EMI read it and contacted the conductor about doing a Gershwin album with Kiri Te Kanawa. "She was looking for a follow-up to `Blue Skies' and they were looking for an arranger. I said, `Why? You've already got the best arrangers there are, Gershwin and Robert Russell Bennett.' Well, that went so well they said, `We'd like you to record some shows.' DG had just done `West Side Story' and CBS `South Pacific' - I think they were feeling a little left out. So, thinking this chance would never come my way again, I said, `OK, I'd like to do `Show Boat.' "

If the Gershwin album was a success, "Show Boat" proved to be a smash. Not the usual collection of highlights, it was the first complete recording the score itself - generally acknowledged to be Kern's masterpiece - had ever had. Were that not enough, it also featured, for the first time since the 1930s, the original lyrics and orchestrations and, by means of a 62-minute appendix, alternate versions of some scenes as well as songs written for other productions, including the 1936 Universal film.

Within a year it had pulled down nearly every major record award in the English-speaking world, paving the way for further McGlinn-led explorations of the original versions of such shows as "Anything Goes" and, most recently, "Sitting Pretty" and "Kiss Me, Kate."

In addition he found himself invited back to Carnegie to conduct restored versions of "No, No, Nanette" (Vincent Youmans), "The Cat and the Fiddle" (Kern) and Gershwin's "Primrose" - its American premiere - and "Pardon My English." At the request of Mrs. Richard Rodgers, he restored and conducted the original 1937 version of "Babes in Arms" (Rodgers & Hart) and recently, on public television, could be seen leading the Boston Pops in a program of songs from many of these same shows.

Well, this week it is the Utah Symphony's turn, as McGlinn takes the podium for an evening of "Broadway Show-Stoppers" Thursday, March 28, at Brigham Young University's Harris Fine Arts Center and Friday and Saturday, March 29 and 30, at Symphony Hall. Starting time for each is 8 p.m., with tickets available at the respective locations.

Included will be such Rodgers & Hart standards as "My Funny Valentine," "Johnny One-Note," "The Lady Is a Tramp" (all from "Babes in Arms"), `Falling in Love With Love" and "Bewitched, Bothered and Bewildered," along with a Cole Porter sequence that will include, besides the "Kiss Me, Kate" Overture, "Begin the Beguine," "I Love Paris" and "I Get a Kick out of You."

Joining McGlinn will be soprano Kim Criswell, his partner on several of the show albums listed above. And, as is the case there, everything will be heard in the original orchestrations.

"I always do them that way, if they exist," McGlinn says. "Which means that usually when I do a concert about half the string section gets the night off. But it also means you're going to hear them the way they were performed the night of their world premieres. That means in their original keys and at the tempo the composer intended.

"That's not to say people like Kim and Judy Kaye and others I work with don't have personalities - they do. But what I hope when I perform this material is that the composer's and the lyricist's personalities are paramount. Let's face it, when you hear Frank Sinatra or Ella Fitzgerald sing `I Get a Kick Out of You,' those performances are telling you more about the performers than about those songs."

If that sounds like a strange position for a Broadway-oriented conductor to take - Broadway, where so much of the time the performer is king - well, McGlinn didn't start out that way.

A self-described "social-register brat" from Philadelphia's mainline, his first exposure to music came by way of the Gilbert & Sullivan 78s his parents had lying around the house. Soon he found himself attending his first G&S opera and, at the still-tender age of 10, bartering his lunch money for a piano/vocal score of "The Mikado."

"What are you going to do with this?" he remembers his mother exclaiming when she discovered what he'd spent his money on. "You can't even read music."

Undeterred, McGlinn returned to the music store, hungry for more. And one day, when they still couldn't fill his order for "Patience," he succumbed to another title, in this instance "Das Rheingold" by someone named Wagner."I thought it must be about a brewery," he says. But back home, as he began leafing through its pages, "The Ring" began to work its magic. "Here it was, set at the bottom of the river Rhine amid swirling mists - you can imagine the effect of this on a 10-year-old child." Soon followed the score for "Die Walkuere" and, as the gift of a school chum who hadn't been similarly enraptured, the Solti recording of "Das Rheingold."

The result was that by the time he reached college McGlinn didn't want to be a conductor - he wanted to be an opera singer. "Here I was with this sweet little tenor voice, and I wanted to be Siegfried," he says, with evident amazement at his own chutzpah. But eventually that led him into dramatics ("I'm probably the only working conductor with an Actors Equity card") and theory and composition. In Europe to visit the Bayreuth Festival, he found himself working as a "gofer" on the movie version of Harold Prince's "A Little Night Music" and, from that point on, Broadway and Wagnerian scholarship were wedded.

"Arthur Laurents once said he started directing in self-defense," McGlinn explains, "so he could see his work performed the way he wanted it. I suppose that's how I started conducting. I realized that if I were going to hear `Sitting Pretty,' `Oh, Lady! Lady!!' and `The Firebrand of Florence' I was going to have to do it myself instead of waiting around for Michael Tilson Thomas to do it."

"Show Boat," he admits, has proven a tough act to follow. Nonetheless upcoming projects include a recording of Kurt Weill's "Love Life" ("for my money the greatest score he ever wrote"), the first musically complete recording of "Oklahoma!" and a Leroy Anderson album that, in addition to the world premiere recording of his Piano Concerto, will feature the songs and dances from "Goldilocks."

As for the original orchestrations, are they really that important? We know, for example, that Bennett - who between 1922 and 1971 orchestrated more than 200 shows - never took them or his own contribution all that seriously. Richard Rodgers, moreover, later sanctioned updated versions of several of the shows he had done with Larry Hart, as did Jerome Kern with even such an ambitious undertaking as "Show Boat."

In reply McGlinn cites one of the songs to be heard on the Rodgers & Hart segment of this week's program, "Ship Without a Sail." "When I discovered the original orchestration of that," he says, "it went from being a terrific song to being a great song. Because in arranging these songs for their first performances, the men who did it were not trying so much to highlight an individual personality as to zero in on the specific emotional content of the songs themselves.

"In this song, for example, you'll hear a lonely chime, like a buoy in the distance, every other bar. Two years ago I went to Monte Carlo for the first time - I had never been to the Mediterranean before - and I remember coming home from dinner one night and sitting on the rocks and hearing a buoy in the darkness and thinking, `That's the most lonesome, forlorn sound I've ever heard. This must be how black and dark it was in the lifeboats the night the Titanic went down.' Well, when I heard this orchestration the first time that's the image the sound of that chime brought back to me, and that's just one note.

"OK, maybe not one person in a hundred would hear it that way. And I realize there are people who openly scoff when they hear me talk about Gershwin, Kern and Cole Porter the same way as Wagner, Strauss, Mozart and Chopin. Some of them probably did care less about this kind of thing than I do. But not Kern. He was obsessive about it. I once asked his daughter Betty what he would have thought about what it is I do, and she said, `Secretly, in his heart of hearts, he would have been thrilled, because you are taking his music as seriously as he did. But because you're so serious about it, he would have used it as an excuse to tease you unmercifully. He would never have let you know how pleased he was.' "