She's the top:
[t]heatre producer Vinton Freedley saw her perform and invited her to audition for the role of San Francisco café singer Kate Fothergill in the new George and Ira Gershwin musical Girl Crazy. Upon hearing her sing "I Got Rhythm", the Gershwins immediately cast her, and Merman began juggling daytime rehearsals with her matinee and evening performance schedule at the Palace.http://en.wikipedia.org/...
Girl Crazy opened on October 14, 1930 at the Alvin Theatre, where it ran for 272 performances. The New York Times noted Merman sang "with dash, authority, good voice and just the right knowing style," while The New Yorker called her "imitative of no one." Merman was fairly blasé about her notices, prompting George Gershwin to ask her mother, "Have you ever seen a person so unconcerned as Ethel?", and he made her promise never to work with a singing teacher.
Anything Goes proved to be the first of five Cole Porter musicals in which Merman starred. In addition to the title song, the score included "I Get a Kick Out of You", "You're the Top", and "Blow Gabriel Blow". It opened on November 21, 1934 at the Alvin Theatre, and the New York Post called Merman "vivacious and ingratiating in her comedy moments, and the embodiment of poise and technical adroitness" when singing "as only she knows how to do." Although Merman always had remained with a show until the end of its run, she left Anything Goes after eight months to appear with Eddie Cantor in the film Strike Me Pink. She was replaced by Benay Venuta, with whom she enjoyed a long but frequently tempestuous friendship.
Merman initially was overlooked for the 1936 screen adaptation of Anything Goes when Bing Crosby insisted his wife Dixie Lee be cast as Reno Sweeney opposite his Billy Crocker, but when she unexpectedly dropped out of the project Merman was given the opportunity to reprise the role she had originated on stage. From the beginning, it was clear to Merman the film would not be the enjoyable experience she had hoped it would be. The focus was shifted to Crosby, leaving her very much in a supporting role. Many of Porter's ribald lyrics were altered to conform to the guidelines of the Motion Picture Production Code, and "Blow Gabriel Blow" was eliminated completely, replaced by a song Merman was forced to perform in a headdress made of peacock feathers while surrounded by dancers dressed as Chinese slave girls. The film was completed $201,000 over budget and seventeen days behind schedule, and Richard Watts, Jr. of the New York Herald Tribune described it as "dull and commonplace," with Merman doing "as well as possible" but unable to register "on the screen as magnificently as she does on the stage."