Shazam! Just how does it work?
Ever heard a song and wondered who was singing? or the name of the song?
Shazam is a cool little app you can put on just about any “smartphone” device. It listens to whatever sound it can (using the built-in microphone, hence the “smartphone” part) and compares what it hears to a vast library of music. Finding a match, it shows you the artist, title, album art, and of course links so you can buy the music (usually through iTunes or Amazon).
How do it know?
Many years ago music was recorded in an analog environment. Everything was mixed and put down on some type of tape. Over time, those tapes became smaller and smaller, ending up with cassettes that gave you very portable music.
Then the digital age gave us CDs (compact discs). CDs do it differently. All of the music is stored in a digital format (think 1′s and 0′s and computers). CD players read those 1′s and 0′s and convert them back into music (just like your computer is reading the 1′s and 0′s of this article and converting them into letters, etc). The end result is a music format that doesn’t degrade over time. Remember when you played your albums over and over as a kid, and before long they started sounding scratchy, etc? That degradation was eliminated with digital music. It either plays, or it doesn’t. Scratches on CDs don’t sound like scratches, they just prevent the reader from interpreting the 1′s and 0′s and therefore stop playing (we’ve all had a CD that wouldn’t play because of a scratch).
What’s this got to do with Shazam? A friend of mine suggested that Shazam works by transmitting whatever it hears into a large room of music experts. They identify the music and type in the answer, which gets transmitted back to you. Of course that would work at some level, and it would actually work whether the music was digital or analog (you could hear a live band playing a song and figure out what the song is). But that’s not how Shazam works.
Shazam listens to the music and converts it back to its original digital format. Since it’s just 1′s and 0′s (I’m simplifying a bit) all it has to do is pattern match those 1′s and 0′s back to a library of digital music. If it finds a match, then it knows the artist, album, title, etc. Letting Shazam listen to a live performance, even if it’s the original band at a concert, it won’t match the digital signature of the recording in the library.
In the same way a microphone and speaker just do the opposite of each other, you can take an analog signal (what you hear) and turn it back into a digital signal. It actually happens a lot. Cell phones do the same thing.
If you have a smartphone, and don’t have Shazam, give it a try. It’s a fun way to learn new music without having to always ask someone “what’s that song playing now?”
