How does Shazam do it's thang?

[BeatLeSS]

I was thinking just tonight about getting Shazam, cos you know, there's a lot of music out there that you just wish you knew the name of. But I got thinking about whether or not it would actually pick up my style of music and if it'd be a good buy if it didn't. I became curious as to how it does it's thing and makes it 'that' app for it's niche, and stumbled upon this. Thought it worth sharing.

That Tune, Named":21hylxps]First, a short explanation of how Shazam works. The company has a library of more than 8 million songs, and it has devised a technique to break down each track into a simple numeric signature—a code that is unique to each track. "The main thing here is creating a 'fingerprint' of each performance," says Andrew Fisher, Shazam's CEO. When you hold your phone up to a song you'd like to ID, Shazam turns your clip into a signature using the same method. Then it's just a matter of pattern-matching—Shazam searches its library for the code it created from your clip; when it finds that bit, it knows it's found your song.

OK, but how does Shazam make these fingerprints? As Avery Wang, Shazam's chief scientist and one of its co-founders, explained to Scientific American in 2003, the company's approach was long considered computationally impractical—there was thought to be too much information in a song to compile a simple signature. But as he wrestled with the problem, Wang had a brilliant idea: What if he ignored nearly everything in a song and focused instead on just a few relatively "intense" moments? Thus Shazam creates a spectrogram for each song in its database—a graph that plots three dimensions of music: frequency vs. amplitude vs. time. The algorithm then picks out just those points that represent the peaks of the graph—notes that contain "higher energy content" than all the other notes around it, as Wang explained in an academic paper he published to describe how Shazam works (PDF). In practice, this seems to work out to about three data points per second per song.

[Scottie]

Isn't it free anyway? I always just assumed it was black magic though

[Cupe]

Yea I'm pretty sure it's free. They get money from referrals to track purchases

[BeatLeSS]

It's free? I thought it cost heaps!

[Mitch]

Free bra

[Narukami]

It's free yeah and it's honestly the best thing in the world. Found so many awesome tunes thanks to this nifty thing

[BeatLeSS]

Grabbing it now

Still cool to know how it does it's thing though!

[yizzle]

It's free yeah and it's honestly the best thing in the world. Found so many awesome tunes thanks to this nifty thing

2nd that

[wrxfiend]

I use it almost daily, when i hear some old dope track i wanna sample.

My missus listens to ol fart radio, goldmine for samplers.

[Kodiak]

I like Soundhound for the fact you don't even need to listen to the genuine source material (ie you can sing or hum into it). But not long ago Shazzam teamed up with Beatport so has a much, much bigger library of EDM.

Although I find I use it a lot to find out what that song is that has probably been on top of the charts that everyone else already knows the name of.

[BeatLeSS]

[eggssell]

oh wow. so it doesnt just transmit to a sweat shop filled with filipino teenagers. well ill be

[yizzle]

LOL!