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 1978, the famed Chicago Blues All Star Band put on an electrifying performance at the North Sea Jazz Festival in The Hague. In this short clip, they are joined by guitarist Eddy Clearwater who plays a stunning cover of "Everything's Gonna Be Alright.