Beck was born in Montreal in 1968/1969 as Jean-Christophe Beck. He attended Crescent School in Toronto, Ontario, Canada and studied music at Yale University, serving as the music director of its a capella groups the "Spizzwinks(?)" and the "Whiffenpoofs," the latter holding the distinction as the oldest collegiate a capella group in the United States.
Beck studied film scoring at the University of Southern California Thorton School of Music, taught by Jerry Goldsmith, among others. He then studied and worked with Mike Post for some time, writing some music for some of Post's series, though he was uncredited. In 1998, Beck won an Emmy Award for his work on the television series, Buffy the Vampire Slayer, where he served as the main composer during seasons 2-4.
- Beck said he tried to incorporate the tunes of Robert and Kristen Lopez's songs as instrumental themes in the score to create a more cohesive musical experience; the goal was the create a connected musical idea as opposed to it simply being, "Okay, now it's a score's turn, now it's a song's turn, now it's a score's turn..." The ending song of the film, "Epilogue" is a particularly good example of integrating themes from other songs.
- Beck felt that the character of Elsa provided the most musical opportunities because of her intense emotions combined with her magical powers.