The music changes in the English anime are atrocious.
The scene where Serena cuts her hair is a prime example.
American:
https://www.youtube.com/watch?v=-SKxZUM7gWc
Japanese:
https://www.youtube.com/watch?v=2hxJKbQKwqw
The American composer (Ed Goldfarb) is really bad about creating an atmosphere with his music. It's all very one-note "Oh this is happening, have to play this music now. Oh this character is talking, have to play their theme now" as opposed to making each shot feel like a part of one cohesive scene. The contest judge (Palermo) has this theme in the American dub that plays every time she's onscreen even though her presence in this scene is meant to give focus to Serena. The Japanese track on the other hand really builds throughout the scene and does a great job at telling the story in its own way that complements the onscreen visuals. The American music is far too erratic and specific to do that. Plus the fact that most of the Japanese music (as this piece does) comes from the games just unifies the franchise where there's no such connection in the dub.
They keep the music when Ash and the gang see her new hairstyle, so why couldn't they keep Az's theme earlier in the episode? Shit's stupid. 4Kids was able to keep most of the music in the first few seasons, I don't know why Pokemon Company can't.