Jacob Gershvin, George Gershwin's real name according to his birth registry, began his music career when he was 16 years old by playing piano in music stores to demonstrate new popular songs. He later studied piano with Ernest Hutcheson and Charles Hambitzer in New York and studied harmony with Edward Kilenyi and with Rubin Goldmark. Gershwin was an almost immediate success with his song "Swanee." Gershwin also studied counterpoint with Henry Cowell and with Joseph Schillinger. Schillinger's influence can be seen in many of Gershwin's pieces, particularly in Porgy and Bess, an opera written for black singers using African American musical styles. Rhapsody in Blue, for piano and jazz orchestra, is another ground-breaking piece, incorporating jazz and blues sources and idioms in the classical concerto style. His song "I Got Rhythm" has been performed thousands of times in hundreds of ways by jazz musicians. His brother, Ira, wrote the lyrics for many of his songs. His melodic talent and genius for rhythmic invention are what made Gershwin an important American composer. He died at the age of 38 of a gliomatous cyst in the brain. Every year on the anniversary of his death, Lewisohn Stadium in New York holds a memorial concert.