"Infectious" is too mild a word for viral tunes like "Hip Hopallula" and "Hello," which both owe a sizable debt to old-school Grandmaster Flash and Whodini. In fact, odds are good that Junior Senior's brain trusts, Danes Jeppe Laurson and Jesper Mortensen, are likely be quarantined in the National Jewish TB ward if they even attempt to travel abroad with finely synthesized carry-on like this. The lyrics on Hey Hey My My Yo Yo, the duo's latest, are blissfully goofy, with no fewer than three party dance numbers employing the ABBA "dance/chance" rhyme scheme, including one "pants" trifecta. Recalling Lipps Inc. and the Sylvers, the joyous disco here is expertly conceived to shake even the most cynical booty: "We R the Handclaps" replicates the Jackson 5 with innocent honor, while "I Like Music (W.O.S.B.)" is a clever, self-referencing girl-group celebration of the songwriting process. Violin, guitar, electronics and shakers flesh the thing out nicely. Junior Senior is a lot like processed cheese from a can: You know it's disgusting, but it's too damn good to resist.