1. Kanye West bids you good night, and good luck.

As the ways we listen to music evolve, so do the methods by which musicians try to mess with their audience. Take, for instance, the “pre-gap track,” a phenomenon that’s all but disappeared in the age of iTunes and Spotify and FaceTweets and TumbleBooks. Most music CDs contain a quick, barely-there track stored before the album’s first song kicks off — traditionally two seconds of absolute silence, invisible to most CD players — but a number of artists cleverly realized that they could hide actual music in that soundless gap, accessible only by rewinding from the album’s earliest point. For instance, walking controversy Kanye West hid this remarkably soothing Mos Def collab on his 2007 effort, “Graduation,” which stands as a stark contrast to the darker, more introspective songs that make up most of the album proper.

2. A Radiohead mindfreak ten years in the making.

Oh, that wacky Thom Yorke. When he isn’t staring joylessly into rainy window panes, there’s a chance the rascally Radiohead frontman is plotting out decade-spanning musical projects meant to blow your feeble human mind. As most diehard Radiohead fans (Radiohead-heads?) could tell you, there was a strong overarching theme of “tens” surrounding the band’s 2007 release, “In Rainbows” — it was announced ten days before release, there are ten letters in the title — capped off by the fact that it came out ten years after another of the group’s landmark albums, 1997’s “OK Computer,” another title with exactly ten letters. So what does any of this mean, exactly? When shuffled together with a ten-second crossfade between tracks, the albums go really, really well together. A bit too well, actually, like they’re two halves of one big, beautiful whole. For extra mind-boggle-ocity, the two titles, when combined, leave us with this clever anagram:

“Combination Super Work”

Far-reaching fan conspiracy theory or meticulously plotted masterwork? The world may never know.

3. Janelle Monae’s hidden gem.

Seeing how funk-a-tronic soul songstress Janelle Monae is most certainly a robot herself, it’s really no surprise that abstract track “Neon Gumbo,” off her full-length debut record “The ArchAndroid,” only makes a lick of sense when played from back-to-front. When spun forward it’s a backmasked mass of eerie chants and looming keystrokes, but when reversed it reveals itself as the climax to “Many Moons”, a fast, feverous single from the singer’s first EP.

4. Pink Floyd appreciates your effort, really.

There’s something wryly ironic about a backmasked musical message that openly mocks those that hunt for backmasked messages in music. Then again, “wryly ironic” has kind of been Pink Floyd’s M.O. since day one. A knowing wink to the industry’s infatuation with “satanic messages” hidden in popular tunes, Pink Floyd pointman Roger Waters hid this clever call-out in “Empty Spaces” on The Wall, congratulating keen-eared listeners on, er, finding his clever call-out. Hey, sometimes a cigar is just a cigar.

5. The “Inception” soundtrack finds a new way to blow your mind.

Though the throttling BRRRRMs and BRAAAAMs of Christopher Nolan’s twisty-turvy blockbuster were inescapable during the summer of 2010, only a handful of film fans noticed that those striking chords had a…deeper meaning. Moviegoers will likely recognize Edith Piaf’s seminal “Non, je ne regrette rien” as the tune that jolted Nolan’s dream-divers back to reality, but what happens when that same song is slowed down and turned way up? One word: SONGCEPTION.

6. Mew offers up two tracks for the price of one.

Backmased messages are one thing, but only a handful of enterprising artists have endeavored to mix entire hidden songs into their singles. (And no: despite what the Internet tells you, slowing down “Call Me Maybe” by like a million times doesn’t count as a “hidden song.”) The opening track on “No More Stories,” the latest album from Danish trio Mew, is a hopeful effort filled with swelling, springy instrumentals and nigh-intelligible lyrics from frontman Jonas Bjerre. Reversed, it becomes a new track entirely — an anxious affair backed by billowing chords and a guarded, almost apprehensive air.

7. The Mars Volta puts an eerie spin on a classic nursery rhyme.

So, a couple of quick questions: 1) Did you know about the spine-tingling, sing-song rendition of “Itsy-Bitsy Spider” stowed away on The Mars Volta’s debut EP?, and 2) You weren’t planning on sleeping tonight, were you? The fledgling prog-rockers sampled an old record of children’s nursery rhymes on the track “Eunuch Provocateur” — spun backwards for maximum creepiness — then steeped it in harrowing guitar plucks and a jittery drum machine to really capitalize on that “Mother Goose by way of David Lynch” vibe.

8. Mindless Self Indulgence only wants what’s best for you.

Okay, okay; it might not necessarily count as a “hidden” backmasked message when the title of the song is, er, “Backmask.” Still, synthpunk prodigies Mindless Self Indulgence obviously enjoyed hiding some surprisingly sound advice in this seemingly by-the-books track. Despite it’s shrieking, violent vocals, a reverse playback reveals a stream of subtle backmasked messages, including such pearls as “eat your vegetables,” “do your homework,” and “don’t sit close to the T.V.” Subliminal self improvement…who knew?

9. Tool hides a track within a track within a track.

This one’s a doozy. Unlike the above artists, who opted to sneak in songs and messages either during or before their tracks, alt-rock act Tool snuck an eleven-minute masterpiece onto their last album, but spread across three wildly different songs. So how does that work, exactly? When said three tracks are played concurrently — “10,000 Days” for its full eleven minutes, set against “Wings for Marie” and then “Viginti Tres” — the songs crescendo into a complementary clash of writhing guitar chords and suitably epic shredding. The end result is something like finishing a jigsaw puzzle while kick-flipping on a flaming skateboard: everything fits into place perfectly, and you feel awesome doing it.