Shazam turns 20

For many it will be a surprise to learn that Shazam, that app that became popular shortly after the arrival of the first smartphones (at the end of the first decade of this century) is as old as it seems knowing that today marks its 20th anniversary. And yet that’s how it is and, what’s more, the origins of the company that was formed to start working on this technology are even earlier, dating back to 1999.

In its early days, first in the United Kingdom (its creators were students from Berkeley, California, but they worked at an Internet consulting company based in London) and later also in the United States, the service worked through phone calls and text messages. The user had to make a phone call and transmit up to 30 seconds of the song to be identified, which were processed by the first version of Shazam. Once the piece was identified, the user received an SMS message with said identification.

The initial name of the service was 2580, since this was the short number that had to be dialed to use it. In the response message, in addition to the title and artist, the service later began to also add direct purchase/download links to the identified song. To use the service in the United Kingdom, in 2006 the cost of a call and the reply message was £0.60although a modality of flat rate for £4.50 per month.

During his early years Shazam reached agreements with several operators, but everything changed with the arrival of smartphones and app stores. Apple was interested in the service from the first moment, to the point that the Shazam app was part of the apps offered in the App Store from the first day it was launched. Shortly after, it made the leap to Android and other platforms that no longer exist, such as Windows Mobile and Blackberry OS.

Between 2008 and 2017, the company signed several agreements with various online music stores, given that from the first moment it was verified that the percentage of users who bought a song after identifying it with Shazam was unusually high. But everything changed at the end of 2017, when Apple announced that it was going to acquire the company for 400 million dollars. The European Commission reviewed the acquisition and finally gave its approval in September 2018, at which time the operation was completed. Since then, Shazam is a subsidiary company of Applealthough the service is still available on other platforms, such as Android and Windows (in this case through a browser extension.

How does Shazam work?

Explained in a simple way, the service analyzes each song and generates a unique fingerprint based on the frequency of each of the most notable sounds that make up the song and the time in which it occurs. To do this, a spectrogram is used, which is subsequently converted into what the system’s creator calls a “Constellation Map”. This map, in turn, is used to create multiple markers of two frequencies with the time of separation of the first with the second. This process is graphically represented in the paper which defines how Shazam’s identification system works:

For each song, Shazam generates multiple fingerprints, creating a hash for each one.. In this way, when we use Shazam to identify a song, the app records and processes that sound, carrying out a process similar to the one described above. As you can already imagine, during it what it does is generate the hashes of the tracks of the song and, at this point, it only has to cross the data of this recording with its database of hashes of all the songs indexed by this system. Thus, only a sufficient number of matches will be necessary for identification to occur.

This is, as I indicated at the beginning, a basic description of how Shazam works, If you want to go deeper, you have two very interesting ways to do so.. In case you prefer a complete but entertaining and friendly explanation, my recommendation is the video dedicated to Shazam that Jaime Altozano published a few years ago. On the other hand, if you prefer a deeper knowledge, although it is also a bit more arduous, you can consult the paper published by Avery Li-Chun Wang, one of the creators of Shazam, in which he explains its operation in detail.