by Stewart MasonThe artsy hard rock group Pavlov's Dog spanned progressive music and heavy metal in much the same way that Rush did in its early days. Also like Rush, Pavlov's Dog had a singer, David Surkamp, whose distinctive high-pitched voice was the group's take-it-or-leave-it factor. Outside of a small cult following, most folks chose to leave it, but over the decades Pavlov's Dog has remained a popular find for fans of the obscure end of American arena rock.\r Pavlov's Dog formed in St. Louis in 1972 out of the ashes of a local cover band called High on a Small Hill, with Surkamp, formerly of the minor folk-rock act Touch, on vocals and guitar, joined by lead guitarist Steve Scorfina; keyboardist David Hamilton; Mellotron and flute player Doug Rayburn; bassist Rick Stockton; drummer Mike Safron; and strings specialist Siegfried Carver (born Richard Nadler), who added violin, viola, and an odd hybrid instrument called a vitar (th...