By now, you probably know the basics about this year's Grammy nominations, which were announced on Friday. Jay Z has more nominations than any other artist (nine). Macklemore & Ryan Lewis have the most in the marquee categories (three). Daft Punk is the only act to be nominated for both Album of the Year and Record of the Year.

But this year's nominations list raises some questions too. What exactly does this mean for the music business? Let's solve this year's big Grammy mysteries...

What do the nominations tell us about trends in music? One major trend they highlight is the rise of collaborations. All five of the nominees for Best Pop Duo/Group Performance are collaborations. (In other words, none went to ongoing groups or duos.) Collabos also accounted for a majority of the nominations in these five categories: Best Dance Recording, Best R&B Performance, Best Country Duo/Group Performance, Best Americana Album, and Best Blues Album.

Another trend the nominations highlight is the way artists nowadays move from genre to genre. Pop queen Kelly Clarkson is nominated in the country field for "Don't Rush," a collabo with Vince Gill. Pop and R&B veteran CeeLo Green is nominated for Best Traditional Pop Vocal Album for CeeLo's Magic Moment. Hip-hop star Snoop Dogg (now known as Snoop Lion) is nominated for Best Reggae Album for Reincarnated. Rock legend Brian Eno is nominated for Best New Age Album for Lux.

Why wasn't Justin Timberlake nominated for Album of the Year? That's this year's million-dollar question. Timberlake was nominated for seven awards this year, but he was shut out in the marquee categories. His first two solo albums, Justified and FutureSex/LoveSounds, were both nominated for Album of the Year.

Timberlake's camp entered The 20/20 Experience—The Complete Experience, which combines the original album (which is the best-selling album so far this year) and the sequel, which drew tepid reviews and has been a sales disappointment. It's possible that the second installment tarnished the reputation of the first. It's possible that if Timberlake hadn't released the sequel, or if his team had simply entered the original album instead of The Complete Experience, he'd be sitting today with his third consecutive Album of the Year nomination.

But aren't the Grammys all about sales, at least in the major categories? Obviously, songs and albums that are familiar have a huge advantage over songs and albums that are little-known. If you haven't heard it, you're not going to vote for it. Looking at this year's five nominees for Record of the Year, the single with the lowest sales tally is "Get Lucky" by Daft Punk featuring Pharrell Williams — and it has sold just under 3 million copies.

Three of the five nominees for Album of the Year are million-sellers — no easy feat nowadays.

But the panel also strives to "give a shot" to deserving albums and artists that haven't sold nearly as well. Sara Bareilles's The Blessed Unrest (a surprise Album of the Year nominee) has sold a modest 204K copies to date. And James Blake (a jaw-dropping Best New Artist nominee) has sold just 46K copies of his album, Overgrown.

Miley Cyrus didn’t get any nominations. Did her tabloid adventures hurt her Grammy chances? Probably. Cyrus's two 2013 smashes, "We Can't Stop" and "Wrecking Ball," are highly credible works, especially coming from an artist that most had all but written off. The tabloid exploits stepped on the main story, which was Cyrus finding her niche as a grown-up pop star.

Looking at similar female pop stars, Madonna also had to wait awhile for Grammy recognition. She wasn't nominated until her seventh single, the ballad "Crazy For You." By contrast, Katy Perry and Lady Gaga didn't have to wait at all. Both were both nominated for their first hits.

Why was Robin Thicke's "Blurred Lines" nominated for Record of the Year but not Song of the Year? (And what's the difference between the two awards, anyway?) I'll answer the second question first. Record of the Year is for a specific recording of a song. Song of the Year (which goes to the songwriter) is for the song itself.

"Blurred Lines" is strongly reminiscent of Marvin Gaye's 1977 smash "Got To Give It Up (Pt. I)" — so much so that Gaye's family has sued for copyright infringement. With this split decision, the panel that determines the final nominations in the top four categories (Album, Record and Song of the Year, and Best New Artist) seemed to be saying, "The song is derivative, but you can't deny that the single is catchy and well-crafted."