[120bits]

I was wondering, does Shazam can differentiate well between these two songs? I'm not entirely sure about the internal working of it, but was curious to know how these pattern recognition apps can help in this.

Also, reminds me of the Silicon Valley where Richard was able to disproof Patent troll by using his music/search app.

[lukecameron]

The technique you're looking for is Acoustic Fingerprinting [1]. There's a pretty easily understandable python implementation[2] of it if you're interested. In Shazam's case it is looking for peaks in the sound's spectrograph, so I don't think it would likely confuse two songs based on melody alone. It would have to be very close in rhythm, melody, and possibly even be in the same key.

[1] - https://en.wikipedia.org/wiki/Acoustic_fingerprint [2] - https://github.com/worldveil/dejavu

[uw_rob]

From my understanding, Shazam can differentiate between songs that share samples by doing classification on a windowed section of input. I.e, take 5 seconds of recording, and classify on t=0..2, 1..3, 2..4, 3..5. The idea being that the sample usage won't continue forever, and you will eventually get a new pattern. (You can even use your classifications from t=0..2 as priors for future classifications!).

For an easy intro to how Shazam works, see this: https://www.toptal.com/algorithms/shazam-it-music-processing...