I like it myself... waaay back before Glee killed TV musicals, you kind of had to expect that almost all children's cartoons do at least one musical episode during its run (anyone remember what was originally the second-to-last Dexter's Lab episode where the whole thing played out like an opera?)

My only quibble with it was Brain's music video was really the only one that seemed to have any kind of real effort put into it: both Arthur and Mr. Ratburn's music videos were pretty much clips and flashbacks.