How does Shazam work?

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

by datadrivenangel • 3 months ago

171 40 3 months ago

perthirtysix.com

cellular• 3 months ago

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

gnabgib• 3 months ago

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

cyral• 3 months ago

The interactive parts of this post are very cool though

BLKNSLVR2• 3 months ago

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.

Animats2• 3 months ago

Vaguely relevant pop-culture reference.[1]

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

eichin• 3 months ago

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

swyx• 3 months ago

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...

Animats2• 3 months ago

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...

bitexploder• 3 months ago

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

andai• 3 months ago

Why is this harder than "delete timing information" ?

Gigachad2• 3 months ago

"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.

dataviz1000• 3 months ago

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

dackdel• 3 months ago

voodoo

thakoppno2• 3 months ago

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?

krustyburger• 3 months ago

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?

thakoppno2• 3 months ago

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.

zevyoura• 3 months ago

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

wood_spirit• 3 months ago

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

blackjackfoe• 3 months ago

No "AI" required!

G_o_D• 3 months ago

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

knodi123• 3 months ago

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.

Gigachad2• 3 months ago

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

krishna_dam• 3 months ago

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

yawpitch• 3 months ago

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

flyuk• 3 months ago

Nice article - enjoyed reading!

larodi2• 3 months ago

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

old_bayes• 3 months ago

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.

larodi2• 3 months ago

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.

SilverElfin• 3 months ago

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.

rmnclmnt• 3 months ago

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?)

sandos• 3 months ago

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?

nunez• 3 months ago

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.

IAmBroom• 3 months ago

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

wrxd• 3 months ago

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!

shriracha• 3 months ago

Thank you!

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

dexihand• 3 months ago

Cepstrum mentioned

y1zhou• 3 months ago

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!

How does Shazam work?

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