Very well put together musical homage, but what I recently realised that I particularly like about it (musically) is that is uses the leitmotifs from, mostly, the soundtrack to the first movie.

According to the video’s own description:

0:01 Hedwig’s Theme
0:12 Mr. Longbottom Flies
0:22 Prologue
0:32 Aunt Marge’s Waltz
0:47 Buckbeak’s Flight
1:00 Double Trouble
1:19 The Face of Voldemort
1:29 Hedwig’s Theme