Go to the magazine website and start reading. Become familiar with the writers who are reviewing music. The writers reviewing national acts are going to be more difficult to reach, so follow the magazine's trends and be ready to submit your music when a new writer joins the staff. You will know if the writer is new by counting the number of articles he has published with the magazine.
Research the writer on the Internet. If the writer is serious, he will have a profile on LinkedIn or Google Profiles. Use these tools to find the writer's public e-mail address. In addition, most of the writers have Twitter accounts linked directly to their reviews on the URB website. If the writer has a Twitter account, start following him and tweet upcoming shows and reviews from other publications.
Send the writer an e-mail. In the subject heading, note the name of your band and a brief statement of the style of your music. Use the subject heading as an opportunity to appeal to the writer's interests. You know what bands the writer enjoys based on his reviews. Compare your band to one the writer has reviewed.
Make the body of the e-mail brief and to the point. Address the writer by name and state that you are an avid reader of his reviews. Briefly summarize your band's key accomplishments and describe the music, making sure to once again reference a band the writer has previously reviewed.
Conclude by the thanking the writer for his time and provide a link to your website. Attach an mp3 of your best song and send the e-mail.