USA Today's Steve Jones had an article yesterday about rap's falling album sales. It's a well researched article that gets past the cliches and gathers a variety of opinions (including mine). KRS-One said the public is choosing not to buy because "the music is garbage" -- which is about the only cliche in the article. (There has been bad music throughout time. The '80s and early '90s, recalled as some kind of golden era, produced hits from both Kid 'n Play and Vanilla Ice.) Chuck Creekmur of AllHipHop.com thinks there is a lack of variety. Felicia Palmer, founder of SOHH.com, thinks labels' singles-dominated strategy has failed in the digital era.

Music consultant Tom Vickers perfectly captured the problem:

"Rap has gradually degenerated from an art form into a ring tone. It's a hip catchphrase or a musical riff with a short shelf life. It has a novelty element that captures the listener's imagination, but it's not a song. It won't build a career. That's why we're seeing this backlash."

In November of 2006, I had a post about hip hop's transformation into a singles and ringtones business. The reaction that post got showed me people weren't very aware that rap was underperforming as a genre. In the months since, there has been a good deal of debate and articles on the matter. So far this year, rap's album sales decline has actually accelerated.

My take has not changed. Rock has done far more to capture the music consumers who I would call the "independents," those people whose music purchases vary according to broad trends and shifts in taste. (They're like the undecided voters before an election.) Rap will always have its core base, but the crossover fans aren't listening to rap as much as they used to. Those middle class kids in the suburbs have elected to take their dollars elsewhere.

There is no single reason. Rap's decline comes from a confluence of changes. Maybe it's a generational thing. Maybe there's an online disconnect -- have you seen the terrible online presence of most hip hop artists? Maybe it's a result of the change in tastemakers: From rap-friendly retail to rock-friendly iTunes; from MTV to "American Idol;" from Rolling Stone to a fragmented landscape of rock-loving blogs and websites. Maybe it's a lack of hip hop tours and a glut of rock bands criss-crossing the country. Maybe it's because trend-setting shows like "Grey's Anatomy" have soft rock and not hip hop.