“This paper investigates the effect of MP3 compression on music emotion. We conducted listening tests to compare the effect of MP3 compression on the emotional characteristics of eight sustained instrument sounds. We compared the compressed sounds pairwise over ten emotional categories. The results show that MP3 compression strengthened the emotional characteristics Sad, Scary, Shy, and Mysterious, and weakened Happy, Heroic, Romantic, Comic, and Calm. Interestingly, Angry was relatively unaffected by MP3 compression.”