Lars Gunnar "Lasse" Lönndahl was a Swedish singer and actor. He was considered the most well-known Swedish singer of the 1950s and 1960s with nicknames including "The Swedish Frank Sinatra" and "World's Oldest Teenager". Even though by the mid-1970s his career had slowed down, he was still considered arguably Sweden's most popular singer of all time and was long a very popular figure in media.