Lars Erik ("Lasse") Dahlquist (14 September 1910 – 14 October 1979) was a Swedish composer, singer and actor. Many of his songs are among the most popular sing-along songs in Sweden, such as Oh boy oh boy oh boy and Gå upp och pröva dina vingar. Lars Erik ("Lasse") Dahlquist (14 September 1910 – 14 October 1979) was a Swedish composer, singer and actor. Many of his songs are among the most popular sing-along songs in Sweden, such as Oh boy oh boy oh boy and Gå upp och pröva dina vingar.