The music of Johann Speth (1664-1719) has featured here and there on many compilations of instrumental music from mid-17th century Germany. However, until now there has never been a complete recording of the sole collection which carries his name down to us today. Published in 1693, this volume of keyboard toccatas, partitas and Magnificats takes it's title from an influential treatise on the science and aesthetics of music from 1650 by the Jesuit scholar Athanasius Kircher. Kircher attempted to show how the balance of dissonance with consonance in harmony mirrored the presence of good and evil in the universe. There is in turn something attractively compendious about Speth's musical response, which Speth appears to have produced as a bona fide for his successful application to become organist of the cathedral in Augsburg. Very little is known of his life until that point in 1692, and not much after, save that in 1719 he was still living and active in the city which at the time was politically significant and prosperous as a seat of the Hapsburgs Ars Magna Consoni et Dissoni opens with a sequence of 10 toccatas, quite brief and owing something to the influence of contemporary southern German composers such as Georg Muffat and Johann Caspar Ferdinand Fischer. There follows the more Italianate strains of three 'partitas.' The remainder of Speth's collection synthesizes Italian and German styles in eight Magnficats. Each of the Magnificats takes it's tonal base - the equivalent of it's key signature - from a different musical mode, each starting on their own note. The collection as a whole adds up to a colorful snapshot of the invention and variety of German keyboard music beyond Bach, and as a notable predecessor to the compendious ambitions of The Well-Tempered Clavier.