Harold Samuel Shapero (April 29, 1920 – May 17, 2013) was an American composer.
Shapero was born in Lynn, Massachusetts on April 29, 1920. He and his family later moved to nearby Newton. He learned to play the piano as a child, and for some years was a pianist in dance orchestras (Kennedy 2006). With a friend, he founded the Hal Kenny Orchestra, a swing-era jazz band.

He was more interested in classical music. In his teens he some of his teachers included Nicolas Slonimsky (editor of Baker's Biographical Dictionary of Musicians) in 1936 and Ernst Krenek in 1937 (Tommasini 2013). At 18 he entered Harvard, where he became friends with Leonard Bernstein and studied composition with Walter Piston in 1938 (Tommasini 2013). He also studied with Paul Hindemith at the Berkshire Music Center in 1940–41 (Pollack 2001).

Shapero was one of the first students at Tanglewood following its founding in the 1940s. When Igor Stravinsky was Norton Professor at Harvard in 1940, Shapero showed Stravinsky his Nine-Minute Overture.[citation needed] Shapero hoped to get the Overture played at Tanglewood that summer, but Hindemith ordered that no student compositions would be played that season. Aaron Copland hastily put together an orchestra to play student compositions, including Shapero's Overture.[citation needed] Shapero was awarded the Rome Prize in 1941 for his Nine-Minute Overture, which included a $1000 award. World War II prevented him from taking advantage of the residency in Italy the prize provided (Anon. 1941).

At Harvard he held the Naumberg and Paine Fellowships. After graduating in 1941 (Anon. 1946b), Shapero undertook further studies with Nadia Boulanger at the Longy School of Music in 1942–43 (Pollack 2001). While studying with her, Shapero was also in contact with Stravinsky, who was helpful in his critiques of Shapero's music.
Shapero's output was prolific in the 1940s and included three piano sonatas, the Sonata for Violin and Piano, and a variety of songs and works for chamber ensembles. His major work was the Symphony for Classical Orchestra, 45-minute work in four movements (Tommasini 2013). Decades later, he told a New York Times interviewer that was unaware while composing it of how lengthy it had become, that he "had wildly miscalculated my materials. When I measured out the slow movement, I was shocked. It was 15 minutes. I stopped working for a month. Then I tried to cut the thing. But it fought me and won. Slowly I became aware, with horror, of what I was writing: a long and difficult symphony. I thought I'd never get it performed" (Tommasini 1999). In 1946 Shapero won the Joseph H. Bearns Prize of US$1200 for the Symphony for String Orchestra (Anon. 1946b). Leonard Bernstein "fell in love" with the work and led its premiere with the Boston Symphony Orchestra in January 1948. Georg Szell, though far less enthusiastic about the work, gave its second performance with the Cleveland Orchestra in March. Reviews were mixed (Tommasini 2013). It received an award from the Koussevitsky Foundation (Tommasini 1999). Bernstein recorded the work in 1953, but it was largely forgotten until revived in 1986 by André Previn to positive reviews. Previn recorded the work and played it several times with other orchestras (Tommasini 2013).

In 1945, Shapero married the painter Esther Geller. Throughout the rest of the decade they were often residents at the MacDowell Colony in Peterborough, New Hampshire (Ng 2013). In 1946 he won the second annual George Gershwin Memorial Contest for his Serenade in D (Anon. 1946a), which included a performance of one movement from the work at Carnegie Hall on February 13, 1946. The prize also included publication of the score with royalties and US $1000. It was the first time Shapero had a score published.

Aaron Copland thought highly of Shapero's technical skill and the spontaneity of musical inspiration. Once, after being impressed with Shapero's Woodwind Quintet, he teased Leonard Bernstein, who was two years ahead of Shapero at Harvard with a note: "Look to your laurels! There may be another composer in your neighborhood!" (Tommasini 1999). But in a 1948 New York Times article, he wrote: "Stylistically, Shapero seems to feel a compulsion to fashion his music after some great model. Thus, his ... Serenade ... is founded upon neoclassical Stravinskian principles, his three Amateur Piano Sonatas on Haydnesque principles, and his recent long Symphony [for Classical Orchestra] is modeled after Beethoven.... [H]e seems to be suffering from a hero-worship complex—or perhaps it is a freakish attack of false modesty" (Copland 1948).

In the 1940s Shapero was closely associated with fellow Piston students Arthur Berger and Irving Fine in a "Stravinsky school" of American composers—a phrase first coined by Copland (Pollack 2001). He was also grouped in the "Boston school" along with Arthur Berger, Lukas Foss, Irving Fine, Alexeï Haieff, and Claudio Spies (Taruskin 1997, 457).

He won a Guggenheim Fellowship in 1946 (Guggenheim Memorial Foundation 2013). He won the first of his two Fulbright Fellowships in 1948.

His output fell off by the 1960s as his neo-classical style met increasing resistance, especially in academic music circles. He told an interviewer in 1986 that "Comfortable university life is a disaster, especially if you have a university that doesn’t pressure you to produce or perish. And I had a young child. I like home handicrafts and hobbies. I like gardening. I like photography. So it was only too easy to put off some of those hard operations like writing music" (Tommasini 2013).

In 1951 he was a Fellow of the American Academy in Rome (American Academy in Rome n.d.(a)). That same year, Brandeis University hired Shapero and he later became chairman of the department and founder of its electronic music studio with the day's most advanced synthesizers. He taught at Brandeis for 37 years (Tommasini 2013). His notable students include John Adams, Gustav Ciamaga, Scott Wheeler, and Richard Wernick.

His daughter, Hannah Shapero, was born in 1953. She became a commercial artist and electronic musician (Tommasini 2013).

When Bernstein and the New York Philharmonic played the local premiere of Shapero's Credo in 1958, a work commissioned by the Louisville Orchestra, Harold Schonberg wrote: "The new Shapero work is in one movement, lasts about eight and a half minutes, ... a quiet and sensitive mood piece, harmonically rather conservative (a Copland type of conservatism, with strong echoes of Our Town), but unmistakably of this generation. Mr. Shapero orchestrates beautifully; some of his combinations are very effective" (Schonberg 1958).

When awarded his second Fulbright Fellowship in 1961, Shapero took the opportunity to travel to Europe with his family for a year. In 1971 he returned to Europe to be composer-in-residence at the American Academy in Rome (American Academy in Rome n.d.(b)).

In 1988, Shapero retired from Brandeis University. Encouraged by André Previn's interest in his work in the late 1980s, Shapero returned to composition. His late works included Three Hebrew Songs for Tenor, Piano and Strings Orchestra (1989) and, not long before his death, 24 Bagatelles for Piano (Tommasini 2013).

Shapero died in a nursing home in Cambridge, Massachusetts, on May 17, 2013, following complications from pneumonia