Did you forget?

          sketch4b.midi           sketch4b.pdf           sketch4b-sheet.pdf
              Refer files;    sketch4b.ly     sketch4b-sheet.latex     run--multiple.cmd      run--multiple.sh
              Actual files Download; sketch4b.tar.gz ( About; 20,150bytes )
       Windows (cmd)>run--multiple sketch4b[Enter]      Linux (bash)$ ./run--multiple.sh sketch4b[Enter]

This sounds "sketch4b.mp3".