Mr. Bloom was born on April 18, 1926, in Cleveland, to Benjamin Bloom, a lawyer, and Emma (Elliott) Bloom, a homemaker. He said the idea of becoming a musician had taken root when his parents had made him attend a concert by the cellist Emanuel Feuermann.

“I walked into that concert not knowing anything about music and not giving a damn about it,” he told Sarah Willis, a horn player with the Berlin Philharmonic, in 2012 when she spoke with him for one of her online “Horn Hangouts” interviews. “And I walked out of that concert at the age of 12 and I knew what I wanted to do with my life.”

He started learning the cello. But then came the war, and he entered the military.

His parents told him to learn the horn so he could join a military band to avoid being sent to the front. He did, and he spent the war playing in a Navy band in Illinois. His wife said he would later joke that “playing the French horn saved his life.”

After the war he attended the Eastman School of Music in Rochester, but he left after two years when he won an audition as the principal horn in the New Orleans Symphony, which he joined in 1949. He moved on to the Cleveland Orchestra in 1954 and was appointed principal there soon afterward when the Chicago Symphony tried to poach him.