Activity

One of my favorite things about the Baroque style was the practice of teaching composition by the method of “aliter fac”, (do otherwise), i.e., taking a theme from one of the masters, and developing it in an entirely different way. JS Bach did this all the time, and in some of his most famous pieces. A “little” example, if you can stand about 20 minutes of organ music. First, the Prelude and Fugue in B Minor, BWV 544, by JS Bach. Pay particular attention to the fugue subject: https://www.youtube.com/watch?v=ES7fN2lXWHU&fbclid=IwAR2QOAjO7zD9Mxsf8me6EBmdQkxd9JNSGmgnwcNRFN5G63nKoIg2AkA2gQI

And now listen to the transformation of that theme in the hands of his favorite organ and composition student, Johann Ludwig Krebs, who turns it into a monster double fugue in sonata form: first section= subject, second section+ counter subject and both themes combined, third section = theme (upside down)+ theme (right side up) + counter-subject: