Dietrich Buxtehude
The organs that Buxtehude played were very large instruments with bright sounds (bright mixtures, reeds and a “Zimbalstern” which was a star which went round and round, making a tinkling sound).  His music is very grand and impressive.  Many of his organ pieces have several sections, each one at a different speed.  They often sound like a free improvisation.  Some of the sections are fugues. At least 128 vocal works survive, they are nearly all church music.  He wrote instrumental works, chamber music and pieces for harpsichord.