Later northerners like Franz Tunder, Georg Böhm and Johann Adam Reincken all cultivated a harmonically and rhythmically complex improvisatory style rooted in the chorale improvisation tradition. Forms such as the organ prelude (a multi-sectional composition with numerous flourishes and embellishments such as scale runs, arpeggios and complex counterpoint) and the chorale fantasia (a musical setting of a whole verse of the chorale text, resulting in a multi-sectional composition with contrasting sections for different lines) were developed almost exclusively by north German composers. Dieterich Buxtehude's work represents the pinnacle of this tradition; the "praeludia" form the core of his work. Nikolaus Bruhns was the most important of Buxtehude's pupils, but he died early and only a few works by him survive.