Together with his identical twin brother Andy (Andrew), he began their musical careers at age six with their first appearance on their uncle's television series The Andy Williams Show. They had "the perfect American childhood" until their parents divorced when they were 13.

They became quite popular in the USA after appearing in an episode of the Partridge Family. They are nephews of singer Andy Williams (Moon river). David realized he was gay at 19, but only later, with the support of his brother and father, has he decided to speak out. In 1994, David did an interview for The Advocate announcing he was gay.