Background: Dan Gerhard Brown was born on June 22, 1964 in Exeter, New Hampshire. He has a younger sister, Valerie (born 1968) and brother, Gregory (born 1975). Brown attended Exeter's public schools until the ninth grade. He grew up on the campus of Phillips Exeter Academy, where his father, Richard G. Brown, was a teacher of mathematics and wrote textbooks from 1968 until his retirement in 1997.
Context: After graduating from Amherst, Brown dabbled with a musical career, creating effects with a synthesizer, and self-producing a children's cassette entitled SynthAnimals, which included a collection of tracks such as "Happy Frogs" and "Suzuki Elephants"; it sold a few hundred copies. He then formed his own record company called Dalliance, and in 1990 self-published a CD entitled Perspective, targeted to the adult market, which also sold a few hundred copies. In 1991 he moved to Hollywood to pursue a career as singer-songwriter and pianist. To support himself, he taught classes at Beverly Hills Preparatory School.  He also joined the National Academy of Songwriters, and participated in many of its events. It was there that he met Blythe Newlon, a woman 12 years his senior, who was the Academy's Director of Artist Development. Though it was not officially part of her job, she took on the seemingly unusual task of helping to promote Brown's projects; she wrote press releases, set up promotional events, and put him in contact with people who could be helpful to his career. She and Brown also developed a personal relationship, though this was not known to all of their associates until 1993, when Brown moved back to New Hampshire, and it was learned that Newlon would accompany him. They married in 1997, at Pea Porridge Pond, near Conway, New Hampshire.  In 1994 Brown released a CD titled Angels & Demons. Its artwork was the same ambigram by artist John Langdon which he later used for the novel Angels & Demons. The liner notes also again credited his wife for her involvement, thanking her "for being my tireless cowriter, coproducer, second engineer, significant other, and therapist". The CD included songs such as "Here in These Fields" and the religious ballad, "All I Believe".  Brown and his wife, Blythe, moved to his home town in New Hampshire in 1993. Brown became an English teacher at his alma mater Phillips Exeter, and gave Spanish classes to 6th, 7th, and 8th graders at Lincoln Akerman School, a small school for K-8th grade with about 250 students, in Hampton Falls.
Question: When did he become a songwriter?. Whats the answer?
In 1991 he moved to Hollywood to pursue a career as singer-songwriter and pianist.