I recently caught an extensive selection of some popular current songs – my session lasted roughly as long as a Halloween party at an elementary school – and included in the lineup were Miley Cyrusʼ “Wrecking Ball,“ Ylvisʼ “What Does the Fox Say,” Rednexʼ “Cotton-Eyed Joe,“ and Psyʼs inevitable “Gangnam Style.” As a passive listener of unfamiliar material, I was struck by how much the musicʼs reliance on hooks hasnʼt changed, and how much it has.

An effective hook, of course, is the Holy Grail of popular song, something elusive and even indefinable, ever-changing yet rigorously precise. Hooks are those parts of a track that stay in the audienceʼs mind and which, at their simplest level, make the tune memorable The more memorable, the more listeners, and the more listeners, the more sales, airplay requests, or Youtube visits. The Yeah yeah yeah in the Beatlesʼ “She Loves You“ is as infectious a hook as has ever been devised by man, but it is closely followed by the riff in Roy Orbisonʼs “Oh, Pretty Woman,“ the chorus to the Bee Geesʼ “Stayinʼ Alive,“ the arpeggiated chords to Blue Öyster Cultʼs “(Donʼt Fear) The Reaper,“ the guitar lick in the Temptationsʼ “My Girl,“ the keyboard flourish in Warʼs “Low Rider,“ and just about every other number on your local oldies radio station. The better the hook, the bigger the hit, and the best hooks have put their songs into the immortal ranks of “Happy Birthday“ or “Jingle Bells.”

But over the decades, hooks have become less and less built around singing or instrumentation, to a point where today they donʼt even have to be music, strictly speaking. Studio recording equipment and outboard sound effects, certainly, have made hooks for generations: Elvis Presleyʼs “Heartbreak Hotel“ wouldnʼt be the same without its echo, nor the Rolling Stonesʼ “(I Canʼt Get No) Satisfaction“ without its fuzz box, nor the Beach Boysʼ “Good Vibrations“ without its theremin, nor Jimi Hendrixʼ “Voodoo Chile (Slight Return)“ without its percussive wah-wah pedal, nor Queenʼs “We Will Rock You“ without its cavernous stomps. And so with the advent of digital sampling, drum machines, and the other technology available to musicians now, a hook can almost be programmed into the work without needing any human inspiration to come up with it.

Because I heard the latest crop of Top 40 tracks without any knowledge of who was performing them, or without any emotional attachment to their subgenre or their target demographic (two individuals excepted), they registered with me more as sonic signatures rather than songs in the traditional sense. Many were more like stop-start collages of sounds, voices, and rhythms more than verse-chorus-bridge-chorus resolutions, but by some clinical standard I suppose they were no less catchy than the hit parades of 1955, 1967, or 1979. In the same way that Motownʼs Berry Gordy wanted his label to project a single resonance, aimed at the audio capacities of transistor radios, and in the same way that house music was designed for Ecstasy-spiked raves, so is contemporary music structured around the frequencies of iPods and similar accessories. The words and the chords arenʼt meant to linger with the force of the overall production; the message is secondary to the medium.

The cliché complaint, “Thatʼs not music, thatʼs just noise,“ is actually accurate, insofar as each new era redefines exactly what music is or can be. No doubt if Iʼd grown up with Gilbert and Sullivan, I would have perceived Robert Johnson as gangsta rap, and if I was raised on Bing Crosby, Buddy Holly would have seemed like heavy metal. To me, ZZ Topʼs “Tush“ or AC/DCʼs “Live Wire“ are pleasant ditties to hum and tap my feet to; to my grandparents they would have sounded like assaultive, pornographic barrages of decibels. Psy and Ylvis, then, are still hitting the same sensory receptors which have already been worn down by a century of recorded pop music, but itʼs amazing to think of just how much wearing down those sensory receptors have undergone.