Harry Potter and the prisoner of Azkaban [sound recording] : original motion picture soundtrack / music composed and conducted by John Williams.

Enhanced descriptions from Syndetics:

John Williams, when working within the realms of science fiction or fantasy, somehow manages to convey the same level of magic and whimsy inherent in Tchaikovsky's Dance of the Sugar Plum Fairy. For the first two Harry Potter films he employed an instantly memorable theme augmented by a series of elegant yet uninspired action motifs that while effortless were, like the films themselves, merely adequate. Harry Potter and the Prisoner of Azkaban finds the Oscar-winning composer swelled with a creative giddiness that hasn't been present for some time, resulting in a piece of work that's both fully realized and endlessly unpredictable. Beginning with the familiar celesta cue that launches each installment, Williams seems poised to deliver a solid reworking of the previous scores, but that sentiment is abruptly quelled by the jazzy, big-band one-two punch of "Aunt Margie's Waltz" and "The Knight Bus" -- the latter borrows liberally from his outstanding Mancini-esque work on Catch Me If You Can. What follows is an intoxicating fusion of medieval-meets-Rossini-meets-Arvo Pärt mayhem that recalls his Close Encounters of the Third Kind heyday. Director Alfonso Cuaron's youthful enthusiasm has had an effect on Williams, and nowhere is that more apparent than on "Double Trouble," a devious choral piece cleverly built around the prose of Shakespeare's Macbeth and devilishly sung by the London Oratory School Schola Children's Choir. It's this melody, culled from bits and pieces of "Hedwig's Theme" from The Sorcerer's Stone, that permeates the entire score. Williams has a deep understanding of the orchestra, and his love of woodwinds is on glorious display throughout the work's entirety, but they never overplay -- as was often the case in the previous two films -- even the thunderous Kodo-style tympanis that introduce the Hypogriff "Buckbeak" are merely exclamation points announcing the arrival of one of the composer's most beautiful melodies. The Prisoner of Azkaban is thought by many to be the finest book in the series, and it would seem that both the director and the composer agree. Like Cuaron and Rowling, Williams meets his characters -- children especially -- on common ground, allowing them to laugh, suffer, fail, and succeed on their own terms. He may be the author and director's emotional conduit, but he's a master storyteller as well. ~ James Christopher Monger