by: ANDREW L. YARROW
Although Mr. Crawford is only onstage for about 30 minutes of this technically dazzling rendition of the tale of a disfigured, love-crazed composer who lives beneath the Paris Opera House, his virtuosity as both actor and singer is a major reason that ''Phantom'' opened last week with a record $18 million in advance ticket sales.
Despite handicaps imposed by three layers of foam latex glued to his head to simulate gruesome scars and deformities, and the contact lenses -one blue and one white - that make his vision foggy while performing, Mr. Crawford has grown accustomed to his face. He has worn it since ''Phantom'' opened in London in October 1986 and will wear it for at least nine months more on Broadway. ''It's not painful, but it's sort of like being trapped in a lift,'' he said, as Tiffany Hicks and Michelle O'Callaghan, his makeup artists, gently daubed his face with oil and peeled off his rubbery artificial skin in his dressing room at the Majestic Theater. ''You have to relax and breathe carefully, so it doesn't affect your voice,'' he added. His blurred vision also makes it tricky for him to disappear through a trap door, cling precariously to a flying gilded angel or scurry down a 35-foot backstage ladder from a perch near the theater's ceiling, he said. Vocal Acrobatics a Challenge
Such physical feats are nothing new, however, for an actor whose resume of death-defying stunts includes near-evisceration by a chariot in the film version of ''A Funny Thing Happened on the Way to the Forum'' and dangling from a 30-foot rope and tightrope walking in the London production of ''Barnum.'' ''When I was cast for 'Phantom,' everybody thought I'd be swinging from the chandelier like Quasimodo,'' he said.
But the vocal acrobatics - which take Mr. Crawford from a high baritone through a resilient tenor to a plaintive falsetto - required three months of training, six hours a day. He had been a teen-age choirboy at St. Paul's Cathedral and a boy-soprano chimney sweep in Benjamin Britten's ''Let's Make an Opera'' in 1957, and had sung in the 1969 movie version of ''Hello, Dolly!,'' but it was only in the mid-1970's that he first took singing lessons.
''It was mind-boggling to think you could use the voice in such a rich and expansive way,'' Mr. Crawford said. ''Andrew pushed me to my limits and beyond. It took weeks, sometimes, just to get one line right. In 'Music of the Night,' where I sing in soft tones, the joy had to be pure. Otherwise, I would sound like a Swiss yodeler.''
In addition to the grueling regimen of vocal training, Mr. Crawford prepared for his ''Phantom'' role by reading Gaston Leroux's 1911 novel and seeing the four ''Phantom'' film versions. ''I generally can't stand horror films, but Lon Chaney's passion was incredible,'' he said, referring to the 1925 silent film. 'Overpowering' Overture
''Before I heard the music, I was very frightened by the role,'' Mr. Crawford continued. ''But when Andrew played the overture to 'Phantom,' it was overpowering, and it gave me the basis for the character.''
To Mr. Crawford, the Phantom -who describes himself in the musical as ''this loathsome gargoyle who burns in hell but dreams of heaven'' - is neither a murderous, otherworldly demon nor an erotic specter. ''He's a tragic figure who is fighting a battle he's not going to win,'' he said. ''Only because no one listens to him, and when he has no other way'' does he turn to violence. ''It's a beautiful love story,'' he said.
Mr. Crawford said he ''hadn't really thought of doing comedy'' when he made his 1962 stage debut in Neil Simon's ''Come Blow Your Horn,'' in the West End of London. ''I was always playing car-accident victims or something bandaged,'' he recalled, ''but I'd never read anything so funny, and I had such fun laughing.'' Audiences found him so funny that he spent much of the next 20 years in comedic roles in films and television series. Watching John Lennon
In the mid-1960's, Mr. Crawford appeared in several Richard Lester films, including ''How I Won the War,'' with John Lennon. During the filming, they shared a house in Spain, and he remembers watching in awe as Lennon wrote ''Strawberry Fields Forever'' sitting cross-legged on the floor.
Mr. Crawford's career veered from comedy to musical theater in 1974, when he was cast as the star of ''Billy,'' a production based on the movie ''Billy Liar.'' He subsequently starred in ''Same Time, Next Year'' and ''Flowers for Algernon,'' but his most celebrated role before ''Phantom'' was as P. T. Barnum in ''Barnum.'' After a two-month stint at the New York Circus School, he spent four years in the physically punishing role, and won his first Olivier Award, the English equivalent of the Tony. (His second came last year for his performance in ''Phantom.'') He was last on Broadway in 1967 in Peter Shaffer's ''Black Comedy.''
Behind the makeup and the expressionless white mask he wears in ''Phantom,'' Mr. Crawford is a tall, slim man with curly red hair and blue eyes. He lives in London near Tower Bridge, and devotes his spare time to his tasks as president of the Sick Children's Trust - which provides accommodations for the parents of hospitalized children - fund-raising for handicapped children, and an occasional escape to his country cottage in Buckinghamshire. He was divorced 14 years ago, and has two daughters, Emma, 21, and Lucy, 19.
After his days as Broadway's Phantom end in October, Mr. Crawford said, ''If I were asked, I'd like to do it elsewhere in the U.S., maybe in Los Angeles.'' And, remembering his long-ago days learning music and theater from Britten, he said, ''I'd love to do 'Peter Grimes' or 'Billy Budd' now that I'm grown up.''