I decided to look at these two pieces, which exemplify Paul Klee's experiments with Abstraction and his bond to drafting and music.  The Fuge in Rot is a painting in watercolour based off of the ornamental Fugues of the Baroque period, where a single ornamented melody is introduced, developed, and recapitulated.  This is evident in the repeating afterimages behind each shape, denoting the repeating melody of a fugue.  Each melody is varied, leading to different shapes, but all are repeated at some point in music, which is reflected in painting.  As each melody and harmony is repeated in the fugue, it's dynamic is softened, which leaves the echo-like effect in both music and painting.  The stark contrast in color, a bright red against black, is perhaps a tribute to Johann Sebastian Bach, one of Klee's favorite composers, who was fond of minor keys.  A minor key is usually darker sounding, stark, and often used in more somber music.  This play on chiaroscuro vividly brings out the sounds of a fugue, where each melody is introduced loudly, then fades away into almost silence.