There is a Gilbert Back [Gilbert Adolphe Dietrich Back] , born 10 Jan 1902, Plovdiv, Bulgaria.
His wife Elizabeth Ruth Adler born in Frankfurt Germany in 1914. Numerous shipping entries showing for him. His occupation is given as a musician on a number of the manifests.
He applied for Naturalization in May 1947 whilst living in Santa Monica, California. His occupation showing as musican. He looks to have arrived in the US in 1946 from Turkey (I think this fits with what I read that he left the Berliner Philharmonic Orchestra and headed for Turkey?). Married Elizabeth Ruth in 1938 in Ankara, Turkey. This was given as his residence when arriving in the US in 1946.
He died in Vienna, Austria on 11 Dec 1967 from sleeping medicine poisoning. He and Elizabeth Ruth were divorced the previous year in 1966. He was cremated in Vienna and his ashes returned to his ex wife Elizabeth Ruth for burial in the US. She was living in San Diego, California at the time.
I don't think there were children from the marriage.
Monica