Zac Efrons vocals were only used for a few lines in the first High School Musical movie soundtrack. The majority of the time it's Drew Seeley singing as Troy Bolton. With AI technology we can now imagine what Zac would have sounded like singing the songs from High School Musical 1 instead of Drew. This AI has been trained from all 3 High School Musical movies, so Zac's voice will sound more mature and developed in this version, compared to the few lines he did sing in the first movie.
For comparison. The original with Drew Seeley and Vanessa Hudgens with Zac Lip Syncing.
