音楽 によって Brook, uploaded によって dabrookman. This isn't up here for being a video (As it is a series of photos) but because this is a fanmade original song, my アドバイス is to open it in a new window and let it play while あなた pop.
This is the song 'I've Got a Theory' from the 'Once More, With Feeling' soundtrack coupled with ディズニー animation. Featuring アラジン as Giles, Belle as Willow, Xander as Phillip, Anya as Aurora, Buffy as Jasmine, and a whole lot of cartoon animals.