If you are on an eclectic music diet -- if you need to listen to a little bit of everything in order to stay in shape -- then The Castle Massacre will feel to you like a multi-vitamin. The Norwegian quintet Ping jump around from style to style, reinventing themselves for each of the album's 15 tracks, yet finding a way to carry forward a strong group identity. Pranksters, mavericks, or geniuses? A bit of all three, it seems. There is a healthy dose of humor in this album, from silly lyrics (made sillier by an approximate use of the English language) to silly melodies, but there are also some very strong grooves, efficient songwriting, and surprises by the ton. The music switches around from electro-pop to heavy prog rock, '70s funk, and Zappa-esque twists. Playing the name game, the best approximation would be "the bastard son of Parliament and Black Sabbath, delivered by Frank Zappa", but that will mean something only if you listen to the whole album -- and it still doesn't account for the electronica influence in the hilarious opener "Bow to the Beagle," or "Inside a Rock"'s back vocal line stolen from KC & the Sunshine Band, among numerous other oddities. Truth is, nobody can possibly explain to you how wacky The Castle Massacre is. However, rest assured that this is not a hodgepodge album, a collection of mismatched snippets. These guys know what they are doing and they do it marvelously well. This is one of the more exhilarating, entertaining albums of 2006.