Fiery and funky, Spark is a 3-minute ride commissioned by conductor Kirk Smith for his daughter, the young viola virtuoso Yvonne Smith, whose stunning YouTube performance of the work has brought Spark's excitement and beauty to thousands of viewers. Says Dorff, "Spark is just a short spark of an idea, designed to peak and conclude within 2 minutes. It has a lot of gritty drive, a polymetric parody of the Bach Suite that I had heard Yvonne play, some flavorings from funk and from the 19th-century...