Ira Gershwin’s scribbled notes demonstrate the care he took to match his words with his brother’s melodies. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

U-M’s collection includes the only known handwritten holograph of Ira Gershwin’s lyrics for the song “Someone to Watch Over Me.” (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

Ira and George Gershwin, in Beverly Hills, 1937, collaborated on their first musical comedy, “A Dangerous Maid,” in 1921. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

At the time of this 1937 photo in Beverly Hills, Ira and George Gershwin had been writing songs together for 21 years. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

When George Gershwin wrote “Rhapsody in Blue,” he envisioned a piece that would require a conductor. Los Angeles, 1937. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

George Gershwin and Ginger Rogers, Hollywood, 1936. The brothers had relocated to Beverly Hills at this time to write for RKO Pictures. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

George Gershwin, pictured in New York in 1935, described one aspect of his creative process as “intensive listening.” (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

Experts surmise George Gershwin was increasingly drawn to Broadway “production” music, starting in about 1917. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

George and Ira Gershwin, pictured in New York in 1928, not only worked side by side, but lived next door to one another for most of their lives. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)

By the time of this photo, taken in Paris in 1928, George Gershwin was a seasoned music professional. He made his first piano roll in 1915. (Photo courtesy of the Ira and Leonore Gershwin Trusts.)