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Re:How the Heck does Shazam work? by cellular on Wednesday April 22, 2026 @11:46PM (#47872066)
I did this for a science project in 1986 on an Apple ][c computer !
Re:How the Heck does Shazam work? by gnabgib on Wednesday April 22, 2026 @11:55PM (#47872115)
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

Re:How the Heck does Shazam work? by BLKNSLVR on Thursday April 23, 2026 @12:07AM (#47872161)
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.

Re:How the Heck does Shazam work? by Animats on Thursday April 23, 2026 @12:09AM (#47872172)
Vaguely relevant pop-culture reference.[1]

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

Re:How the Heck does Shazam work? by BLKNSLVR on Thursday April 23, 2026 @12:27AM (#47872241)
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.

Re:How the Heck does Shazam work? by eichin on Thursday April 23, 2026 @01:08AM (#47872421)
probably the HN-specific "Second Chance Pool" for resurfacing links
Re:How the Heck does Shazam work? by cyral on Thursday April 23, 2026 @12:01AM (#47872139)
The interactive parts of this post are very cool though
Re:How the Heck does Shazam work? by swyx on Thursday April 23, 2026 @12:17AM (#47872201)
related comments from Shazamers

- OG shazam paper https://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf (he has a talk on youtube btw look it up if really care)

- https://news.ycombinator.com/item?id=18069968 shazam employee blogpost

- https://news.ycombinator.com/item?id=38538996 shazam cofounder endorsed explainer

- go algo repro https://news.ycombinator.com/item?id=41127726

as with all ML things... the code is much less % of the value than the data...

Re:How the Heck does Shazam work? by Animats on Thursday April 23, 2026 @12:17AM (#47872202)
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...

Re:How the Heck does Shazam work? by Gigachad on Thursday April 23, 2026 @01:51AM (#47872614)
"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.
Re:How the Heck does Shazam work? by bitexploder on Thursday April 23, 2026 @12:19AM (#47872208)
20 years at least. I remember seeing how Gracenote worked back in the day when I was consulting for them.
Re:How the Heck does Shazam work? by andai on Thursday April 23, 2026 @12:29AM (#47872249)
Why is this harder than "delete timing information" ?
Re:How the Heck does Shazam work? by dataviz1000 on Thursday April 23, 2026 @12:27AM (#47872242)
Add to my list of projects. Dinosaur game but with audible clucks to jump.
Re:How the Heck does Shazam work? by dackdel on Thursday April 23, 2026 @12:29AM (#47872252)
voodoo
Re:How the Heck does Shazam work? by thakoppno on Thursday April 23, 2026 @12:39AM (#47872302)
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?

Re:How the Heck does Shazam work? by krustyburger on Thursday April 23, 2026 @12:47AM (#47872339)
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?
Re:How the Heck does Shazam work? by thakoppno on Thursday April 23, 2026 @01:07AM (#47872416)
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.

Re:How the Heck does Shazam work? by flymasterv on Thursday April 23, 2026 @01:29AM (#47872527)
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.
Re:How the Heck does Shazam work? by w-ll on Thursday April 23, 2026 @01:18AM (#47872473)
Pop. Pop. Pop Up Video.
Re:How the Heck does Shazam work? by zevyoura on Thursday April 23, 2026 @12:31PM (#47877768)
I find Youtube's watch history helpful, having that across everything I watched on my device would be even better.
Re:How the Heck does Shazam work? by wood_spirit on Thursday April 23, 2026 @12:41AM (#47872311)
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

Re:How the Heck does Shazam work? by blackjackfoe on Thursday April 23, 2026 @12:43AM (#47872317)
No "AI" required!
Re:How the Heck does Shazam work? by G_o_D on Thursday April 23, 2026 @12:45AM (#47872329)
Out of curiosity is it possible to prevent shazam like app from detecting maybe by adding noise or any technique ?
Re:How the Heck does Shazam work? by knodi123 on Thursday April 23, 2026 @01:32AM (#47872544)
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.
Re:How the Heck does Shazam work? by Gigachad on Thursday April 23, 2026 @01:52AM (#47872620)
Producers/DJs manage this one by just not releasing their music or edits for ages if ever.
Re:How the Heck does Shazam work? by krishna_dam on Thursday April 23, 2026 @12:49AM (#47872348)
Surprised to see how that got it worked with out all the "AI" bluff
Re:How the Heck does Shazam work? by yawpitch on Thursday April 23, 2026 @12:51AM (#47872355)
This has been explained so many times… a wizard imbued the kid with the powers of Solomon, Hercules, Atlas, Zeus, Achilles, and Mercury.
Re:How the Heck does Shazam work? by flyuk on Thursday April 23, 2026 @12:55AM (#47872375)
Nice article - enjoyed reading!
Re:How the Heck does Shazam work? by larodi on Thursday April 23, 2026 @01:26AM (#47872517)
There's an algo called dynamic time warping (DTW) and is very often overlooked. My wild guess would be is at play @Shazam.
Re:How the Heck does Shazam work? by old_bayes on Thursday April 23, 2026 @01:29AM (#47872530)
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.
Re:How the Heck does Shazam work? by larodi on Thursday April 23, 2026 @05:30AM (#47873737)
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.
Re:How the Heck does Shazam work? by SilverElfin on Thursday April 23, 2026 @02:05AM (#47872674)
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.
Re:How the Heck does Shazam work? by rmnclmnt on Thursday April 23, 2026 @02:21AM (#47872735)
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?)
Re:How the Heck does Shazam work? by sandos on Thursday April 23, 2026 @02:23AM (#47872741)
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?

Re:How the Heck does Shazam work? by nunez on Thursday April 23, 2026 @03:01AM (#47872902)
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.
Re:How the Heck does Shazam work? by IAmBroom on Thursday April 23, 2026 @08:01AM (#47874725)
Also useless on older music. I have used it to no avail for movies and old TV shows.
Re:How the Heck does Shazam work? by wrxd on Thursday April 23, 2026 @02:52AM (#47872868)
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!

Re:How the Heck does Shazam work? by shriracha on Thursday April 23, 2026 @03:00PM (#47880059)
Thank you!

This has been on my list forever, finally added it today: https://perthirtysix.com/rss.xml

Re:How the Heck does Shazam work? by dexihand on Thursday April 23, 2026 @10:23AM (#47876121)
Cepstrum mentioned
Re:How the Heck does Shazam work? by y1zhou on Monday April 27, 2026 @01:28AM (#47918006)
> On the flipside, this "fingerprint" approach is also what makes Shazam work poorly if you just sing into it. You're likely to generate different hashes than the original song, even if you are a very good singer! This is why newer, machine-learning-based systems are built to handle humming and singing, by matching on melody rather than exact frequencies.

So this is why singing/whistling a song to my phone never worked! I've always imagined the tech as some sort of wave pattern matching but the DFT is obviously more efficient for many scenarios. Cool article!