In the first scene of Carlisle Floyd's new music drama, "Willie Stark," rough, tough and scruffy Sadie Burke says, "I never knew there was so much profit in castor oil and liver pills."

Floyd should profit by the hint and give the music a dose of the oil, because the problem in his musical drama, opera, call it what you like, is that the music is some of the most costive to come along in years. It simply refuses to move out of a turgid, lumpy rut. Nearly every time a major speech comes along, Floyd's music becomes so congested that the fine impulse of the text is stifled. For a opera that runs three hours and a quarter including two intermissions, there is a vast quantity of sound but very little music, and this has nothing to do with the fact that there is far too much spoken text.

Floyd has written some fine speeches which, with one exception, refuse to come to musical life. The "Little bitty drug store in the little town" is an embarrassment and "the law's single bed blanket" worse. Writing his own libretto, Floyd has come up with a believable opera text that offers as much political vice and moral corruption as "Rigoletto" and as many power plays as "Rheingold." As a play "Willie Stark" might well be more successful than its music allows it to be as a music drama.

In the new production, sired jointly by the Houston Grand Opera and the Kennedy Center, "Willie Stark" is powerful directed by Hal Prince on an imaginative unit set easily transformed from Gov. Stark's office to the sites of political rallies and southern garden parties. The voice of Norman Thomas, heard over authentic 1930s radio sets, is a vivid touch of class that can bring back to those old enough to remember the days when Huey Long was one of the most powerful men in southern politics -- and the day he was assassinated.

To the people, Stark is a man who has promised and delivered. To those who believe in the law, he is a dangerous demogogue who attained power through ruthless means.

Conductor John DeMain deserves great credit for giving every possible vitality to a score that refuses to leave the ground. He strongly assists the acting singers, taking advantage of any chance for change of pace or color.

Much of Prince's best work is in the handling of the excellent chorus which has the job of looking and sounding like born-again believers in the Willie Stark who the powers of truth and justice want to bring down, and later when they become guests at Judge Burden's garden party. His strengths are as effective with the principals, many of whom will be remembered from the famous movie that starred Broderick Crawford and Mercedes McCambridge.

Fortunately the title role is taken by Timothy Nolen, who looks and sounds born to it. He sings with marvelous control that ranges from a lovely, hushed pianissimo to the rousing fortissimo that makes Stark's fan mail eminently believable. And he acts the part, from chest-thumping speeches to irresistible sexiness with Anne Stanton, just as credibly. It is hard to imagine the long, demanding role done better in any way.

To Nolen goes the only inspired moment in the whole affair. It comes during a long speech to the people of his home town. As he circles the crowd of lifelong friends and admirers, he sings "Come back, Willie, come back home. You've wandered far, you've lost your way." Here, for a few moments, Floyd finds real melodic beauty and Nolen fills it with genius.

There are big scenes for Sadie Burke, Willie's tough but faithful P.R. flack who gets dumped for Miss HighTone Stanton.The juicy part is strongly sung and acted by mezzo Jan Curtis. But surely she need not look quite so seedy. Even in 1935 Louisiana, and though scarred by smallpox, must her hair look so rat-infested? Tenor Alan Kays is right as Judge Burden's Ph.D. son whose disillusionment comes when he finds out the truth of Willie's Iago-like aphorism, that "Form the stench of the diaper to the stench of the shroud there is always somethin' to be found, for man is born in sin an' bred to corruption." It is young Burden who assassinates Stark after the governor causes the older Burden's suicide.

Don Gerrard makes a sonorous judge, but Julia Conwell, looking very much the way Madeleine Carroll used to, sounds rather strident in a role that needs a more sympathetic quality Robert Moulson's Sugar Boy is a well-devised portrait and the many bit parts are well sung and acted. If only there were some music!