Bach wrote the Prelude and Fugue in E flat major – Well-Tempered Clavier book 2 #7 (BWV876). The fugue has 4 voices on the keyboard. I added a fifth voice for flute and/or clarinet and/or viola.
Flute version:
Clarinet version:
Viola version:
Flute sheet music:
Clarinet sheet music:
Viola sheet music: