Frank Zappa loved '50s doo wop music. He grew up with it, collected it, and it was the first kind of pop music he wrote ("Memories of El Monte," recorded by the Penguins in 1962). Cruising with Ruben & the Jets, the Mothers of Invention's fourth LP, is a collection of such music, all Zappa originals (some co-written with MOI singer Ray Collins). To the unexperienced, songs like "Cheap Thrills," "Deseri," and "Jelly Roll Gum Drop" may sound like an average doo wop song. A closer look reveals unusual chord sequences, Stravinsky quotes, and hilariously moronic lyrics - all wrapped in four-way harmony vocals and linear piano triplets. A handful of songs from the group's 1966 debut, Freak Out, were rearranged ("How Could I Be Such a Fool" and "Anyway the Wind Blows" give the weirdest results), and old material predating the Mothers was recycled ("Fountain of Love"). "Love of My Life" and "You Didn't Try to Call Me" became live staples.