Gershwin began to get a few of his songs set into current musical shows and his popularity began to grow. His first big success came in 1919 when Al Jolson helped him promote Swanee by adding tit to his touring show. This same year, Gershwin also completed his first Broadway show La, La, Lucille. During the 1920's, Gershwin's popularity grew as he began writing successful musicals for many well-known performers. Gershwin's music was now taking a new turn. He was writing serious music, which made his musical career take off. Many of the serious works that he was composing became some of his most famous accomplishments in the musical world. His growing reputation writing serious music brought him a steady income. Gershwin's interest in serious music had increased so much that he now wanted to write full-length operas, which he had been contemplating for years. By 1935, Gershwin had successfully written several serious compositions, but it was during this year in particular that his most famous opera, Porgy and Bess, was performed. This opera received mixed reviews and led Gershwin to pursue an interest for films. Gershwin moved to California and wrote several film scores. In 1937, Gershwin became seriously ill. He began experiencing headaches, dizzy spells, and blackouts. Several examinations of his illness ended with negative results. His headaches increased in frequency until he went into a coma on July 9th of that year. A diagnosis of a brain tumor was finally made. Gershwin never came out of the coma, and passed away only two days later on July 11th, 1937 during an operation to remove the tumor. Gershwin was greatly influenced during his lifetime by several musicians. The strongest influence on his life as a musician came during his youth from his instructor Charles Hambitzer. Hambitzer introduced Gershwin to the music of Debusy and Ravel, the early works of Arnold Schoenberg, and classical piano.