Buxtehude was a Danish/German organist and composer of the high Baroque. He was highly sought after as both an improviser and teacher -- the teenage Johann Sebastian Bach once famously walked 250 miles to hear him play. He spent most of his career as the organist of the Marienkirche in Lübeck, where in addition to the young JS Bach he also met Handel and Mattheson. Although primarily remembered today as a composer for the organ (in which field he developed both the mature Prelude and Fugue and Chorale Prelude genres), most of his compositional output was in the field of vocal music. The only music he published during his lifetime was a set of 14 chamber sonatas. Read more: Wikipedia article.