Knutsen & Ludvigsen (Translated names: "Tootson" and "Ludiwood") was a Norwegian singing duo consisting of Øystein Dolmen ("Knutsen") and Gustav Lorentzen ("Ludvigsen"). Writing and performing various songs mostly aimed at children, they released seven albums, two of which received Spellemannprisen - the Norwegian Grammy. They had several #1 hits, including "Grevling i taket", "Hallo! Hallo!" and "Dum og deilig". Since the late 90's, they have enjoyed a cult status among young Norwegians, performing a series of reunion concerts.