This year, 12 songs reached the top of the Billboard singles chart, known as the Hot 100, from Ed Sheeran’s meticulously constructed “Shape of You” to Cardi B’s casual “Bodak Yellow (Money Moves).” Including feature appearances, 14 acts had their first No. 1s, like the electronic dance veterans Daft Punk (as guests on the Weeknd’s “Starboy”) and the Philadelphia firecracker Lil Uzi Vert, whose verse on “Bad and Boujee” by Migos begins with “Yah!” yelped five straight times. The track with the longest run atop the heap — “Despacito,” by Luis Fonsi and Daddy Yankee, featuring Justin Bieber — was sung almost entirely in Spanish.

On the album side, there were No. 1s by Future (with two different LPs in back-to-back weeks), the revitalized and bigger-than-ever LCD Soundsystem, the little-known rapper NF and, of course, heavyweights like Katy Perry, Pink and Taylor Swift.

In other words, the monoculture had so many disrupters that cultural whiplash became the new normal.

The most obvious explanation was that the newfound dominance of digital streaming scrambled the entrenched hierarchies, elevating voices that had long puzzled or offended gatekeepers. With physical and digital album sales as well as track downloads all in free fall, and hip-hop and R&B setting the pace for streaming, major labels and major stars alike were often left scrambling to earn the honors that once came so easily.

Because the rules and norms of this era are still coalescing, the systems could also be gamed and manipulated. Loyal listeners schemed to get their favorites recognized, while sly marketing efforts tried to put a heavy thumb on the scales. In all, the music industry and listener machinations made for one of the most disorienting, and often exhilarating, years of hit music in recent memory. Below are some of the trends, tricks and standout moments, which will surely be built upon in the months to come.

>> Rap as Industry Leader

Nothing streams like a rap banger. And nothing could motor a song up the charts this year — aside from event-releases from Sheeran, Swift and Bieber — quicker than a ton of internet-driven chatter. Using a sample week in November, Nielsen found that streaming was up 59 percent year over year, with 80.5 percent of all music consumption now happening digitally. The biggest beneficiaries were rap stars with loyal followings: Building on the meme-driven success of Rae Sremmurd’s “Black Beatles,” Migos’ “Bad and Boujee” hit No. 1 in January as “raindrop/drop top” jokes became a Twitter sensation.

Other rap smashes to score big this year — notably, with or without Top 40 radio support, which often came later, if at all — included Kendrick Lamar’s “Humble”; DJ Khaled’s “I’m the One,” featuring Quavo, Chance the Rapper, Lil Wayne and Bieber; “Bodak Yellow (Money Moves)”; and Post Malone’s “Rockstar,” featuring 21 Savage, which held the No. 1 spot for eight weeks. We are now firmly within a rap boom, and don’t expect the hit-seeking labels to let up in 2018.

>> Making the Streams Count

Sometimes a grass-roots push, such as the loosely organized social media campaign to vault Cardi B over Swift’s “Look What You Made Me Do,” wasn’t quite enough. In the case of “Rockstar,” which was a smash on Spotify and Apple Music immediately upon release, Post Malone also got a wily assist from his label, Republic Records, which found a loophole on YouTube. While the video service has long been a target of the music industry for its low royalty payouts and pesky copyright infringers, free streams on YouTube do count toward Hot 100 placement. But instead of posting the entire song free, Republic uploaded a version of “Rockstar” that was exactly the same length as the actual track, but featured only its chorus, looped again and again. (It also closed comments on the video, preventing users from explaining to others what was going on.)

In its first few weeks, the video earned more than 40 million plays, contributing to the song’s reign on Billboard’s Streaming Songs chart, which preceded its peak on the Hot 100. The successful tactic even had copycats — Big Sean’s “Pull Up N Wreck,” for one — though YouTube has since had the videos removed and changed its rules, telling Pitchfork in a statement: “any upload of a song intended to mislead a user (preview, truncated, looped) posted on YouTube to look like the original song will not contribute to any charts.”

>> SoundCloud and YouTube: Early Warning Systems

Some of the most ubiquitous rap hits of the year weren’t supposed to be hits at all. While streaming success stories are typically dominated by Spotify, which counts more than 60 million paid subscribers, and Apple, which has some 30 million, the digital underground can be just as influential.

“XO Tour Llif3,” a Top 10 hit by Lil Uzi Vert, began as a freebie on SoundCloud, only to gain so much steam that it left his label, Atlantic Records, no choice but to monetize it. The song eventually made its way to Spotify’s prominent Rap Caviar playlist and reached No. 7 on the Hot 100 in June. Similarly, Lil Pump’s “Gucci Gang” dominated the SoundCloud charts long before it got a proper commercial push, hitting No. 3 in December. YouTube worked in much the same way, elevating to the mainstream harsh and sometimes troubling viral songs like “The Race” by Tay-K, a teenage fugitive; “Gummo” by the controversial Brooklyn rapper 6ix9ine; and “Rubbin Off the Paint” by YBN Nahmir.

This trend may not hold: Billboard has announced that beginning in 2018, streams on unpaid or ad-supported services — like YouTube, most of SoundCloud and Spotify’s unpaid tier — would be weighted less than streams on paid services like Apple Music and Google Play. One potential consequence? Fewer niche rappers rubbing shoulders with Bruno Mars and Sam Smith on the pop charts.

>> In a Year of Streaming, How About Not?

Warning: It may not work for everyone. But for Swift, like Adele before her, this year was not yet time to follow the flock. By keeping her new album, “Reputation,” off streaming services for its first three weeks, Swift guaranteed herself an old-fashioned blockbuster, selling 1.2 million copies in her debut week. In the album’s first three days alone, it moved 925,000 units, some 600,000 as downloads and the rest as physical copies, both of which pay out higher royalty rates than streaming. Nice work if you can get it.

>> Albums as Add-Ons

For other acts whose strengths may not necessarily lie in streaming — in other words, nonrappers — there was the ticket bundle. Though it has been around for a decade, the strategy gained prominence this year as Pink, Perry, LCD Soundsystem, Arcade Fire, Kenny Chesney, Shania Twain and U2 topped the album chart in part by including copies of their new releases with the purchase of concert tickets.

Though the sale counts only if the buyer actually redeems the album, the cost is factored into the ticket price and proved a pretty surefire way to gain a first-week sales boost for these reliable live acts. “About 20 percent to 30 percent of fans tend to redeem their album offers, with most favoring CDs or vinyl over downloads, though nudges on email and social media can drive better results,” Billboard reported.

>> The Remix Comes Through

The big-name remix, another tried-and-true maneuver that found new relevance this year, breathed extra life into a few big hits. “Despacito,” the pop-reggaeton game-changer, was already huge, especially on YouTube and the Spotify global chart, before Bieber’s verse was added. But the remix made it a supernova that led the Hot 100 for a record-tying 16 straight weeks and earned Grammy nominations for record and song of the year. Beyoncé provided a similar bit of magic to J Balvin’s “Mi Gente,” lifting it up to No. 3 from No. 21; she later jumped on Sheeran’s “Perfect,” taking it all the way to No. 1. More quietly, Cardi B’s “Bodak Yellow (Money Moves)” got a crunchtime bump from a Spanish-language remix and one featuring Kodak Black, both of which counted toward the main version’s chart position as it reached its apex.

>> Endless Albums

From vinyl through the peak CD era, album length was often dictated by how much music could fit on the disc. The internet has done away with that constraint, too, leading some artists to pile on the tracks in hopes of racking up the streams. For a juggernaut like Drake, more did indeed mean more: “More Life,” his so-called playlist, was 22 songs long and broke digital records. Chris Brown upped the ante in October with “Heartbreak on a Full Moon,” which came in at 45 tracks, and he even instructed his fans on how to send it up the charts (“leave the album on repeat”), though he failed to reach Drake heights. And a new compilation by the stream-heavy label Quality Control, featuring Migos and Lil Yachty, has 30 songs, indicating that the idea has not yet reached saturation.