In 2001 he participated in the Petrof Competition, where he won first prize. He has performed at the Concertgebouw Amsterdam and was also featured on the international art fair TEFAF in Maastricht. Together with his father, organist Peter Eilander, he formed a piano & organ duo and a pianoduo. In the same year Jaap played piano at the opening by Queen Beatrix of the Nationaal Muziekkwartier in Enschede. This event was broadcasted by RTV Oost. In 2012 he released his first solo cd, followed by a Bach-album, released in 2015.
Jaap Eilander regularly gives concerts, as a soloist and as an accompanist for choirs and singers. As a piano teacher Jaap Eilander was attached to the music school in Hengelo. He has now a private teaching practice in Deventer.