Before she became America's top box-office star by playing its oldest virgin, Doris Day was an instinctive, if untutored, actress and an accomplished, popular singer. In Charles Vidor's Love Me Or Leave Me, she takes on the part of Ruth Etting, the troubled songstress from the jazz age, and her twin talents merge memorably. It's a faultless performance, all the more impressive for staying understated, scaled down. <br /><br />Her co-star, James Cagney, takes the low road; as Marty (`The Gimp') Snyder, a lopsided fireplug of a man, he sizzles with resentment and ignites into rages. Strangely, his scenery-chewing complements Day's underplaying; the tension between their temperaments fuels this dark drama which occasionally resembles a musical but is closer at heart to film noir (Vidor, after all, directed Gilda).<br /><br />A taxi-dancer in a Chicago dive, Day catches Cagney's eye (he holds the linen-laundering concession for the place). Finding she's not the quick pick-up he had in mind, he lands her a job in the kick-line at another nitery he services. When he finds out she wants to be a singer, he arranges for lessons with pianist Cameron Mitchell (who plays the thankless role of the loyal but shoved-aside lover). But Cagney, used to getting what he wants and to browbeating everybody around him into surrender, meets his match in Day. Her quiet determination proves every bit as strong as his bellowing bluster. When it looks like her star is in ascendancy, he becomes her manager, puts her on radio, and snares her a spot in New York as a headliner in the Ziegfeld Follies.<br /><br />They settle into a grudge-match of a marriage, with guerrilla warfare erupting from both sides. (Cagney's Snyder is a marginally less disturbed version of his Cody Jarrett in White Heat.) One of their flashfire fights takes place in her dressing room after a show. Cagney knocks a vase of flowers across the room; Day extends her arm for him to unclasp a bracelet. They bicker some more, with Cagney losing the argument while Day nurses the drink that has become her ally. He leans over and tells her `You oughtta lay off that stuff  you're getting to look like an old bag.' It's the chilliest moment in the movie.<br /><br />In the last third, Day answers a call from Hollywood, which lays the foundation for the unravelling of this messy, nerve-wracking relationship. And if the wrapping up grasps toward the sentimental (with a detour into the melodramatic), it doesn't quite take. Cagney, actor and character, hangs on like a bulldog with a bone. The Marty Snyders never change, and Cagney knows it; he stays the self-deluded small-time hood he started out as, who can't accept that he's driven away a woman he can't believe he loves so much.<br /><br />Day, however, rises to a magnanimity that rings hollow. Her steely self-confidence about where her talents would bring her, and her casual callousness in using Cagney to help her get there, make her final gesture improbable. But when she takes the spotlight, singing `Mean to Me' or `Ten Cents A Dance' (with her feet planted provocatively  defiantly  apart), Day, actress and character, takes it by natural right. The voice isn't quite right  Etting's was reedy and tremulous, Day's big and secure  but the assurance and style are dead on.