The composer of the musical 'The Capeman' is Simon, a five-letter name. The musical was written by Paul Simon, an American singer-songwriter and musician who rose to fame as part of the duo Simon & Garfunkel in the 1960s. The musical was based on the true story of Salvador Agron, a Puerto Rican teenager who was convicted of murder in 1959. It opened on Broadway in 1998 and received mixed reviews.