A friend has asked me to build a site with the following options:

• staff members must be able to add new music and artists to the page
• a gallery must be provided - it is also good if each artist has the ability to have his/her own smaller gallery
• users must be able to vote for artists
• users must be able to alter in discussions (forums or comments sections)
• staff members must be able to blog
• staff members must be able to write articles

I did a small project where i actually implemented all of these features, but I want to use an existing content management system for all of these features so that future developers can, hopefully, more easy extend the website. And also, so that I don't have to provide too much documentation.

I have never developed a website using an external CMS like Drupal or Wordpress and after seeing hours of tutorial videos of both systems, I still can't make up my mind on whether i should :

a) use Drupal 7 b) use Wordpress 3 c) create my own cms

I can imagine that staff members would also want to create content using iPhone or android based mobile devices, but this is not a required feature.

Can someone, with experience, please tell me about their experiences with larger projects like this?

The site will have approximately 400 000 - 500 000 visitors (not daily visitors, based on numbers from last year in a period of 4 months)