I have recently purchased the Galaxy Nexus, and I am extremely happy with it. As part of that purchase, I decided to bring all my music into Google Music. So, I've been using Google Music on my way into and home from work (about an hour total a day) and I am seeing a huge amount of data usage from Google Music. (Everything else combined doesn't come close to what it uses.)
Here is a screenshot of my data management window:
Why is this happening? Is there anything I can do to prevent it from heavily using data like it is?