Valera learned how to play the guitar from his older sister. While in high school, he and his brother formed a band called The Electric Hair and performed in snack houses and music lounges. He quit college at the Far Eastern University and accepted work in Japan. When he returned he joined the parish choir and composed songs for the group. Valera's break came when a song he composed for Rico Puno, "Ako Si Superman," caught the attention of Chito Ilacad, then Vicor executive for production. "Ako Si Superman" (1977) was his first hit single, followed by sure-fire hits like "Naaalala Ka" (1978), "Ayoko na sa 'Yo," "Sorry Na, Pwede Ba?," and "Mr. DJ." Valera became known as Mr. Hitmaker; apart from recordings, he also represented the country in international song festivals and performed in shows abroad with other Filipino artists. In 1984, after several gold and platinum records and at the peak of his career, Valera decided to quit his job and recharge. When he returned to music in 1987, he chose to go into film scoring. He worked as musical scorer in more than 50 movies, also doing the theme songs for many of them. However, the continuing decline of original Pilipino music pushed him once again to compose songs. Upon the request of singer Sharon Cuneta, he wrote "Kahit Wala Ka Na." It was adopted as the title of the movie she was making then and started the trend of using Rey Valera's hits as movie titles and theme songs. His comeback album, "Sa Kabila Ng Lahat," turned platinum in just two weeks' time. He has received numerous awards and citations, among them, the 1982 Presidential Award as King of Tagalog Songs, Entertainer of the Year (1982 and 1983), and Most Outstanding Recording Artist and Most Popular Singer/Entertainer (1983).