The North Sea Jazz Festival, Den Haag, The Netherlands. The North Sea Jazz Festival is the largest indoor music festival in the world, known globally as the event where the past, present and future of jazz are featured within three days. Next to a firm base of jazz as the festivalâs staple music genre, many others, such as blues, soul, funk, or hip hop, pass by. In 1988, acclaimed Brazilian singer and pianist Tania Maria performed with bassist Leonard Traversa and drummer Kim Plainfield at the North Sea Jazz Festival in The Hague. Maria is known for her energetic personality and unique style of singing that draws from a variety of jazz, Latin and pop traditions.