The San Francisco Classical Voice blog took the opportunity to contrast the John Williams and Nic Hooper styles in the series.
On John Williams’ wall-to-wall scoring style:
In fact, the only unscored scenes are when Harry is with his adoptive parents in their humdrum daily existence. There, Harry lives in a joyless world without magic, without hope, and without music. When the magic arrives, in the form of Hedwig and the fateful letters from Hogwarts, the music comes along with it.
On Nic Hooper’s broader stylings:
The appearance of the Dementors brings a dramatic flare from the strings, and a grunting chorus and string line that could have been drawn straight out of a Schoenbergian atonal work. Harry’s magic spell is accompanied not by the celestes and glockenspiels of Williams’s score, but by an unidentifiable electronic sound. And when the attack is over, the music again fades down to nothing. A whole sequence with no immediately identifiable musical structure: such a concept would have been unthinkable in Williams’s musical soundscape.
(By the way my favorite Harry Potter score is definitely #3. And I don’t agree with the premise that John Williams’ style can’t accommodate darker themes. Remember Anakin’s dark deeds in Revenge of the Sith…)