Crosby was born in Los Angeles, California, and grew up in the Humboldt and Sonoma counties of Northern California. He developed a love for classical music after watching the film Amadeus. Then he met a girl named Michelle, and to impress her he learned to play the Beatles' hit "Michelle" on guitar. This sparked his interest in The Beatles, and in rock music in general. Crosby's other influences include Metallica and Joe Satriani. He formed V.A.S.T in 1994.