How do CDs actually work?
There’s a moment in every burgeoning music fan’s life when they look at the stereo playing their favourite record and go, “What’s actually going on in there?!” It’s a hell of a question, especially for those born in the age of the CD. What mad science makes a single piece of plastic that you put into a machine produce my favourite music? You’re telling me that a mini-Beatles isn’t in there singing live for my listening pleasure? That’s clearly the simplest option, ergo it’s the correct one,
Even vinyl records were (slightly) more understandable. The needle brushing the record amplifies the sound that the player makes. If you turn down your player and listen really closely, you can hear the music coming from just the needle. Fun fact: It’s the reason why most turntables have a lid! It’s a literal miracle on the surface but basic physics for those in the know. A CD, though, is another thing entirely.
Nothing musical about a shiny piece of plastic, right? Well, think again because the music on a CD is, in a sense, inside it. The outside is many layers of polycarbonate; this is to protect a layer of aluminium within it that actually does contain the music. On this aluminium is a series of microscopic bumps, and much in the same way that a vinyl record has microscopic that the music is picked up from, this is what the music is picked up from with a CD.
So, how does a CD actually work?
In the CD’s case, however, it reads with a tiny laser instead of a needle. Now, here’s where things get truly wild. The laser beam passes through the CD and reflects off the aluminium layer. Within the player is a sensor that monitors the way the beam’s reflection changes and converts those bits of digital information into music. It’s often worth bearing in mind that just because a form of technology is “obsolete” doesn’t make it any less incredible.
I know that vinyl records are the romantic, cooler option, but CDs are brilliant. For one thing, CDs do, in fact, sound better than vinyl. The reputation that they don’t comes from the industry pumping out hasty re-releases of classic albums and not accounting for CDs being a completely different medium for which the music would need a completely different mix. For another, they were the moment music truly went portable!
The more rugged, practical design of the CD meant that people could take them out of their homes without as much risk of damage as the famously fragile vinyl records had. First into the car and then onto the streets with portable CD players. Cassette tapes did sort of get there first but in terms of the sheer amount of data a disk could hold and how long it could last you? There was no competition.
There’s a good reason that CDs completely changed the face of music for more than two decades, and the only way that we could move past them was by changing the face of music forever. So they may be more passe than the unicycle these days, but next time you’re at your parent’s place, spare a thought for the small technological marvels that make up their music collection.
