His father encouraged him to begin acting when Zac was eleven years old. Efron subsequently appeared in theater productions at his high school, worked in the theater The Great American Melodrama and Vaudeville, and began taking singing lessons. He performed in shows such as ""; "Peter Pan, or The Boy Who Wouldn't Grow Up"; "Little Shop of Horrors"; and "The Music Man". He was recommended to an agent in Los Angeles by his drama teacher, Robyn Metchik (the mother of actors Aaron Michael Metchik and Asher Metchik). Efron was later signed to the Creative Artists Agency. Efron graduated from Arroyo Grande High School in 2006 and was then accepted into the University of Southern California but did not enroll. He also attended Pacific Conservatory of the Performing Arts, a community college located in Santa Maria, California, where he performed during the years of 2000 and 2001. Efron began acting in the early 2000s with guest roles on several television series including "Firefly", "ER", and "The Guardian". In 2004, he began appearing as a recurring character in the first season of the WB series "Summerland". For the show's second season, which aired in 2005, he was promoted to the main cast. He also appeared in some films, including the Lifetime television film "Miracle Run" (2004), for which he earned a Young Artist Award nomination for his performance as one of two autistic twins. Efron's career reached a turning point with the teen musical television film "High School Musical" (2006), which premiered on the Disney Channel in January 2006. The film, which has been described as a modern adaptation of "Romeo and Juliet", saw Efron playing the male lead Troy Bolton, a high school basketball player who feels conflicted when he finds himself interested in participating in the school musical with Gabriella Montez (Vanessa Hudgens), a girl from the scholastic decathlon team. The film, which also starred Ashley Tisdale, Lucas Grabeel, Corbin Bleu, and Monique Coleman in pivotal roles, became a major success and helped Efron gain recognition among teenage audiences. The film's soundtrack was certified quadruple platinum by the RIAA, making it one of the best-selling albums of the year in the United States. Efron's singing talents were disputed when it was revealed that his voice had been blended with Drew Seeley's on the soundtrack, but Efron clarified that the songs (written for a tenor) were written before he was cast and therefore did not suit his more baritone vocal range.