Most providers do block music and "warez" newsgroups. And as far as I know, all free 3rd party Usenet services (like Google Groups) also block those newsgroups. And most paid Usenet services start around $20 a month for extremely limited transfers, and try to make it so it's just not worth it to join, unless you're going for the $50 - $60+/month plans.
Graphic Design / Photography / Web Design
Comcast has offloaded their newgroup service to giganews. Being a comcast customer that was switched over I poked around the giganews newsgroups seeing what they had. They seem to have all of the groups with decent retention and complete multipart articles.
If you want to download significant binary data from a good newsgroup service then expect to shell out $30-60/month for the privilege.