Date: January 6, 2008

The Moment: Cool looking, high-quality headphones weren't a must-have item for most music listeners in 2008: They were something you needed, a tool to make your mobile device work, one that sometimes looked cool, but not much more.

At the 2008 Consumer Electronics Show in Las Vegas, that changed when legendary rapper and producer Dr. Dre—who was more or less absent from the greater music conversation at the time—re-emerged with a new act: Dr. Dre, headphone salesman. And not just a headphone salesman, but one with the finest set of headphones everyone from old 'heads to audiophiles had ever seen, Bose be damned. They had Dr. Dre's endorsement. They played bass. He sat at the studio console with them. They had a red cord. What else did anyone need to know?

The Impact: On July 25, 2008, the first model of Beats by Dre—the over-ear "Studio" model—went on sale for $349 (tax not included). They got decent to not-halfway-bad reviews, with most audiophiles citing the significant bass factor missing from most headphones at the time. They were a busting-the-ball-at-the-seams smash.

Early adopters of Beats turned out to be on-trend, as celebrity endorsements—including Lady Gaga and Lil Wayne—followed, which is to say nothing of the legions of rappers, singers, actors, and athletes who weren't being paid to sport them. Towards the end of 2011, helped by the release of several new (and cheaper) models, annual sales were reported to be somewhere in the $500 million range. From headphones. Safe to say, Dr. Dre and Jimmy Iovine had found their biggest hit ever.

The Upshot: Monster Cables didn't make out so well from the deal when Dre and Jimmy let Taiwainese electronics monolith HTC bring its money in, and broke up with Dre and Jimmy (or, more likely, got broken up with) at the beginning of 2012. But the two rap moguls certainly did, both when HTC put $300 million in, and then again, when HTC sold half its majority ownership stake (thus giving Jimmy and Dre majority control over the company).

Beats by Dre changed the headphone game by turning something essential, but never coveted as an item, into a household luxury item. It could fairly be likened to the music fan's version of bottled water (or at least, if not the headphones, then the hand-over-fist cash Jimmy and Dre made).

More importantly: Who needs the rap game when you've got headphone money? Not Dre, who has yet to make another album since 2001, or the long-awaited-and-probably-never-happening Detox. That said, he will step in to drop bars on the occasional star-studded track and, yes, plug the shit out of his headphones.