The sketchbook images for these two weeks were completed using the same image with different music for each . Often times artists resist creating the same drawing or painting more than once. When a drawing, sketch, or painting of the same subject is duplicated it can be monotonous or frustrating. Using music and different techniques or media to change the "mood" of a piece can make the same project enjoyable instead.
This link shows the studies from Georges Seurat who created over 50 studies before completing the final painting: A Sunday on La Grande Jatte (Art institute of Chicago).
http://www.metmuseum.org/toah/works-of-art/51.112.6
Sketchbook exercise: Choose an image to sketch using your choice of music and media. On a different day, use the same image you used to create the first sketch, but choose a different musical genre and media/technique. Let your second sketch be loose and creative- let go of any "rules" and enjoy the process!