Back in 2004 I participated in a survey by Adobe of their clients in creative markets. When the survey was complete, we were given some brief summaries of the various responses.
“Music is part of your work environment, with most of you enjoying Jazz, Blues, and Classical music while you work.” In a nation dominated by rock, hip hop, country, and the like, it was interesting that in secular creative environments most people tended to listen to more mellow, melodic musical forms. Although part of this may be due to workplace policies against loud, aggressive music, it seems to suggest something about the nature of music to inspire. Personally I find that classical and meditative styles of music really get my creative process flowing, especially when I my creativity is at a low ebb.

