alt.hn

4/20/2026 at 3:04:04 PM

How does Shazam work?

 https://perthirtysix.com/how-the-heck-does-shazam-work

by datadrivenangel

4/23/2026 at 4:39:59 AM

Perhaps obviously this is the same technique that enables ACR on TVs.

It occurs to me that Shazam has such a better reputation online because the intent and consent of the user is honored.

It makes me wonder if there couldn’t be an implementation on TVs that is similar and actually is a net positive for consumers. Basically would customers actually like TV ACR if the data wasn’t just going to sell more ads?

by thakoppno

4/23/2026 at 4:47:20 AM

So the value-add would be the consumer would get to find out the name of the show or movie that’s playing, the same info that also pops up if they hit the pause button?

by krustyburger

4/23/2026 at 4:31:23 PM

I find Youtube's watch history helpful, having that across everything I watched on my device would be even better.

by zevyoura

4/23/2026 at 5:07:12 AM

I was thinking more like interactive content. Do you remember when VH1 had a pop-up music video show?

Shows could synchronize additional content that’d be visible when Shazam mode enabled.

by thakoppno

4/23/2026 at 5:29:15 AM

We did this on Fire Phone for live sports and audio based X-Ray cast info. It was, like everything about that phone, a really fun tech demo.

by flymasterv

4/23/2026 at 5:18:54 AM

Pop. Pop. Pop Up Video.

by w-ll

4/23/2026 at 5:26:46 AM

There's an algo called dynamic time warping (DTW) and is very often overlooked. My wild guess would be is at play @Shazam.

by larodi

4/23/2026 at 5:29:41 AM

Ayyy I used DTW to track bots on a certain social media site. They tend to act in herds so DTW helps smooth out delayed, repeat actions.

by old_bayes

4/23/2026 at 9:30:27 AM

Is a brilliant algo, and also works for multi-dim data. U can choose different distance functions - still works. Perhaps Dijkstra-shortest-path level significant for the robotic/ai era.

by larodi

4/23/2026 at 4:17:20 AM

Recognizing a recording isn't hard to do, because, for the same recording, the chords follow each other with precisely repeatable timing. That's been around for well over a decade. Recognizing a different recording, say, a, cover version, of the same song, is much more work.

Audible Magic claims to be able to recognize multiple performances of the same songs, and even parodies.[1] Using, of course, "AI technology" and much more compute.

[1] https://www.audiblemagic.com/2024/02/07/identifying-cover-so...

by Animats

4/23/2026 at 5:51:10 AM

"Isn't hard to do" is doing some heavy lifting. Obviously on a society level it's simple tech we managed ages ago. But I would bet if you tasked individual devs at building it without looking up the answer, very few could do it.

by Gigachad

4/23/2026 at 4:19:02 AM

20 years at least. I remember seeing how Gracenote worked back in the day when I was consulting for them.

by bitexploder

4/23/2026 at 4:29:12 AM

Why is this harder than "delete timing information" ?

by andai

4/23/2026 at 6:23:45 AM

Well, my latest guess is: not at all.

It has been working "fine" for me generally for popular music. But then I was at a ice skating competition where there were some really nice synth:y music going on in the pauses, and I used Shazam on several of the songs, and I tried several times on each. It did not find a single one correctly.

Either this was unreleased music or very small niched music or something, or Shazam totally failed?

by sandos

4/23/2026 at 7:01:14 AM

Yeah Shazam is mostly useless for songs that aren’t in the streaming apps, I’ve found. but not entirely useless! It sometimes matches me with stuff that’s only on YouTube.

by nunez

4/23/2026 at 12:01:04 PM

Also useless on older music. I have used it to no avail for movies and old TV shows.

by IAmBroom

4/23/2026 at 3:55:52 AM

Again? Oh I see.. SCP (this domain is sus)

From CameronMacLeod (2022) - and much more complete analysis (587 points, 2023, 155 comments) https://news.ycombinator.com/item?id=38531428

Or Slate (2009) (50 points, 16 comments) https://news.ycombinator.com/item?id=893353

by gnabgib

4/23/2026 at 4:07:05 AM

Forgive my ignorance, but what does SCP mean in this context? (my normal go-to of 'secure copy' doesn't fit).

Thanks for the other links, the question in this title is one I've day-dreamily thought about on occasion, but never dug into. Will have a read of all three.

by BLKNSLVR

4/23/2026 at 4:09:13 AM

Vaguely relevant pop-culture reference.[1]

[1] https://scp-wiki.wikidot.com/glossary-of-terms

by Animats

4/23/2026 at 4:27:47 AM

I seem to have wandered into a parallel universe.

I think it'll take me longer to understand WTF SCP is than it will to understand how Shazam works.

by BLKNSLVR

4/23/2026 at 5:08:14 AM

probably the HN-specific "Second Chance Pool" for resurfacing links

by eichin

4/23/2026 at 4:01:22 AM

The interactive parts of this post are very cool though

by cyral

4/23/2026 at 6:52:41 AM

Tangential. This is a cool website, so cool that I tried to subscribe to it in my RSS reader… and it didn’t work.

If any of the authors read this message, please consider adding a RSS feed and you’ve got a subscriber!

by wrxd

4/23/2026 at 4:27:53 AM

Add to my list of projects. Dinosaur game but with audible clucks to jump.

by dataviz1000

4/23/2026 at 3:46:12 AM

I did this for a science project in 1986 on an Apple ][c computer !

by cellular

4/23/2026 at 6:21:43 AM

Might be the best visual explainer of Shazam original audio fingerprinting algorithm from the 2003 paper (I guess they´ve switched to ML models at some point?)

by rmnclmnt

4/23/2026 at 4:45:55 AM

Out of curiosity is it possible to prevent shazam like app from detecting maybe by adding noise or any technique ?

by G_o_D

4/23/2026 at 5:32:41 AM

Not unless your noise is louder at certain dominant frequencies than the source. The article gives examples, but the algorithm basically throws away everything except frequency peaks, in order to make the lookups faster.

by knodi123

4/23/2026 at 5:52:37 AM

Producers/DJs manage this one by just not releasing their music or edits for ages if ever.

by Gigachad

4/23/2026 at 4:49:21 AM

Surprised to see how that got it worked with out all the "AI" bluff

by krishna_dam

4/23/2026 at 4:55:07 AM

Nice article - enjoyed reading!

by flyuk

4/23/2026 at 2:23:46 PM

Cepstrum mentioned

by dexihand

4/23/2026 at 4:43:45 AM

No "AI" required!

by blackjackfoe

4/23/2026 at 4:41:52 AM

Reminds me of Roy Van Rijn’s prototype that got a cease and desist letter! Lots of community disappointment at the time!

https://hn.algolia.com/?q=royvanrijn

by wood_spirit

4/23/2026 at 6:05:28 AM

I feel like it does not work well. Shazam struggles to recognize music in real life environments that have some background noise, even with a lot of time. It’s much worse than the built in music recognition Google’s phones have, for example.

by SilverElfin

4/23/2026 at 4:51:07 AM

This has been explained so many times… a wizard imbued the kid with the powers of Solomon, Hercules, Atlas, Zeus, Achilles, and Mercury.

by yawpitch

4/23/2026 at 4:29:58 AM

voodoo

by dackdel