What Do Marketing Departments Do?

Marketing is not a department, but marketing departments exist and I'm increasingly wondering what they do.

Are they merely administrative ciphers allocating budgets to various out-sourced craft and communication specialists? Given their absence from Board representation, do they contribute to a business's strategic direction (as they clearly should)? And doesn't the dissonance between the skill-sets these activities require and the different focus required to actually think about identifying and meeting customer needs explain the lack of esteem in which marketing is held and the preponderence of bad marketing by numbers?

This week in the UK, the complilation of music's Top 40 has been changed and it is predicted that, for the first-time ever, those rankings will be penetrated by an unsigned band called Koopa. In recent times, the industry has said that regardless of the technological revolutions that have changed music production and distribution, bands need them for their marketing expertise. When asked if their success would faciliate their obtaining a record deal, the lead-singer of Koopa asked "What could a record company do for us that we can't do ourselves?" Interesting times.