After the delightful Aunt Marge's Waltz, The Knight Bus swerves violently in unexpected directions (as it were) with a wild fusion of Attack of the Clones' dizzying Chase Through Coruscant and the jazzy free form of Catch Me If You Can. Its unexpected rhythms take a bit of getting used to, but it's the best music for a purple triple decker London bus I could imagine. So there. As with the score, the trailer made little use of Hedwig's Theme and it's the Elfmanesque song Double Trouble that everyone remembers and pleasingly, the film version is a little extended and a delightful addition to Williams' engaging selection of movie songs. The theme is used elsewhere and makes a little light heartedness out of the darker hues. It also highlights the early music instruments of the Dufay Collective who add a medieval atmosphere to some of the more intimate and lower key cues; an extension and evolution of the Diagon Alley music from the earlier films.
Perhaps the most exciting revelations are the action sequences which, in line with the general atmosphere, are more intense and wild. Williams seems to be moving away from the quite broad orchestration style that became a trademark of his 90's scores and continues the trend toward the kind of intricacy for which he became famous and that is now becoming more frequent, most notably in Anderton's Great Escape from the otherwise rather dour Minority Report. Even the now obligatory Quidditch Match is approached with a renewed vigour, the composer much more attuned to the breathless excitement and danger of Rowling's sporting invention, rather than the more light hearted, heroic treatment previously. Elsewhere, standouts include The Whomping Willow, which includes a subtle hint of Hedwig's Theme beneath the scurrying orchestration, while the second half of the cue, The Snowball Flight, turns in some of the score's most playful material. The same can't be said for the hair raising Werewolf Scene where the brass snarl and the dissonance is piled on thick. Intense stuff for a supposed family film.
The Dementors Converge is undoubtedly the darkest point with spectral chorus and dissonant brass that isn't far removed from some of Close Encounter's more disturbing moments. After a turbulent start, the Finale reprises the gorgeous melody for the Patronus Light (which appears all too fleetingly a few tracks previously), before a slightly downbeat conclusion. Mischief Managed ends in fine style as a grand suite of the whole score, including almost all of the new themes - notably a grand orchestral reprise of Double Trouble, as well as the vocal version - plus brief reprises of some of the more familiar ones. In many ways, Prisoner of Azkaban is a more interesting score than its predecessors and bears up better to repeated listening. True, it is perhaps a touch disjointed, but that's largely a result of the wealth of new material that Williams brings, but it's pleasing that he's moving forward with the series rather than endlessly reprising Hedwig's Theme with a token new theme. With no more Lord of the Rings, likely to be the blockbuster score of the year. A dark and exciting delight.
Rating ~ 
Total Time ~ 68:22