Behold, the humble compact disc. Far from obsolete even today, it was developed as a joint effort between Sony and Phillips and released in 1982, it became the standard music format for an entire generation. Not only that, it became the standard disc for business and game software alike. AOL alone mailed out over a billion free install CDs in the mid-90s. Now, those free CDs are a collector’s item.

Come to think of it, I can’t remember the last time I saw a CD. Maybe when I visited my parents for Christmas. What ever happened to them? And why hasn’t anyone developed a more modern replacement?

To answer this, we’ll take a look at what people used before CDs, and why CDs were better. Then we’ll look at problems with CDs, and figure out what a successor technology might look like.

Why Were CDs Created?

Back in 1982, people were listening to music on audio cassettes, 8-track players, and vinyl records. Cassette players had been around since 1962, and had slowly been capturing the market from vinyl. While cassettes are more durable than records, and more importantly, more portable, they’re still prone to breaking, have much lower sound quality, and tend to wear out quickly.

8-track cassettes had existed since 1968. They offered much better quality than standard cassettes, but were bulkier and couldn’t hold as much music. 8-tracks were particularly popular for singles, or for professional radio DJs.

In the realm of computers, some PCs were using reel to reel tapes. For home use, these drives were being replaced by 5 ¼” floppy discs. These discs offered much better read/write speed than tapes, because a tape drive has to rewind and fast-forward the tape to switch between files. On the other hand, they had very little capacity, only 1.44 megabytes, not even enough to hold a single MP3 file.

This wasn’t much of an issue for PC users in 1982, since most PCs of the 80s couldn’t even play music, much less store a meaningful number of files. However, capacity became an issue as early as 1992, when Windows 3.1 required six floppy discs for install. Compare this to the much more advanced Windows 95, which could be installed from a single CD.

How Were CDs Designed?

In 1979, engineers at Phillips called a press conference to announce that they’d developed technology to store audio digitally on an optical disc. Sony, being Sony, immediately proposed a partnership. In 1982, the companies jointly released the first CD player. 50 albums were released on CD at the same time. The very first music CD to sell was a copy of Billy Joel’s 52nd Street.

The technology was an immediate hit with music fans, because it solved all the problems with cassette tapes. Cassettes start to degrade the first time you play them, while CDs will theoretically last for more than a century. Cassette players frequently eat tape, destroying your favorite album. If your CD player destroys a disc, you’re doing something seriously wrong or experiencing a one in a million malfunction.

CDs also have much better audio quality than cassettes. Sony and Phillips designed them so well that to this day CD audio is considered the standard for “lossless” digital music. This is because they made two important decisions.

First, they chose to sample audio at a rate of 44,100 Hertz. Basically, a CD works by taking a “snapshot” of the audio wave 44,100 times every second. The reason this number is important is because it’s more than 10% faster than the rate needed to capture sounds at 20,000 Hz, which is the upper limit of human hearing. Faster sampling rates would capture more information, but only small animals would even be able to hear it.

Another choice they made was to use a bit depth of 16. The bit depth refers to how many bits are used to measure the audio wave in each sample. If a sample is a “snapshot”, then the bit depth is the resolution of that snapshot. Simply put, nobody can tell the difference between 16 bit depth audio and higher bit depths. It’s the audio equivalent of a 4K Ultra HD VR image. There’s just nothing that’s meaningfully better.

For computer users, CDs first started to be used by companies for long-term storage. At the time, the average PC had a hard drive capacity of 10 MB, compared to the 700 MB capacity of a much smaller CD. This made CDs the hot new choice for financial institutions, IT firms, and other companies with boatloads of storage needs.

As home computers became more powerful, software developers started sending out software on CD instead of on an entire stack of floppy discs. This happened over the course of a few years in the early 90s, but at the time it felt like it was happening overnight. By 1995, CDs were everywhere.

Problems With CDs

Of course, no technology is perfect. CDs are no different, and have several flaws which have led to their gradual decline.

To begin with, while they’re the gold standard for digital audio quality, the sound still isn’t as pure as the original analog master. Hardcore audiophiles clung to vinyl, to the point where most current albums are released on CD and vinyl, but not on cassette.

For another thing, even the best CD players can be prone to skipping if you jiggled them, like during a workout or while mowing the lawn. This made MP3 players extremely popular even when they were far more expensive than a CD player, and helped that market explode earlier than it otherwise would have.

In terms of portability, CDs were the best thing around until MP3 players and flash drives became common technology. Does anyone really miss the days of flipping through a binder of CDs while driving, trying to figure out which one to put in the player? Or going on a trip, and deciding which few albums to take with? CDs were easier than dealing with, say, a turntable, but they’re nowhere near as portable as an MP3 player.

For long-term storage, CDs have proven to be less reliable than originally believed. The vinyl outer layers can degrade in as little than a decade, exposing the inner aluminum disc surface to the air and oxidation. Hardly the 100-year security that CD manufacturer’s originally promised.

Not only that, but other storage methods have continued to get smaller. The 10 megabyte PC of 1982 has evolved to the 1 terabyte PC of 2019. To put things in perspective, you’d need a stack of 1497 CD-ROMs to equal the storage capacity of a low-end modern desktop. Unless you’re planning on using an entire garden shed for data backup, this is no longer efficient.

The same thing is true for software installs. Adobe Creative Suite 6, for example, requires 3 GB, or more than 4 CDs worth of data. Popular strategy game Civilization VI requires 13 GB, or 19 CDs. Even if you don’t want to download your game from Steam, do you want to juggle 19 different CDs during the install? Far better to use a single, 25 GB Blu Ray for sending large files through the mail.

What Would a CD Replacement Look Like?

Now we’ve identified everything that’s wrong with CDs. If we were going to design a successor technology, what would it look like?

It might have higher sound quality. Of course, as we discussed, we run into problems doing this with a digital medium. People have been trying for 37 years, and we’re still waiting. As things stand, there’s still no better digital technology in terms of raw sound quality.

If we couldn’t make it higher quality, we’d at least design a system where songs didn’t skip while you were jogging. Of course, cassettes already did that, but we didn’t like the sound quality. We’d need a data source that didn’t rely on a mechanical motor spinning a drive under a reader, so a traditional hard drive would also be a poor replacement. In 1982, we didn’t have the technology for anything better.

In terms of portability, in 1982 we’d probably be thinking about a more advanced optical disc with a more sensitive reader. This would take some time, but it’s certainly something we could get done over the course of a decade or two.

The same solution would apply for long-term storage. Of course, large, reel to reel tapes were still perfectly viable for long-term storage as well in 1982, and were used well into the 2000s by even the largest companies. They held a lot of data for the size, and read/write speed is less of a concern when you’re only using the tape for emergencies and not for everyday use.

For software installs, we’d probably do much the same as people have done in real life. First DVDs, then Blu Ray discs have continued to grow in capacity, and remain the standard for brick-and-mortar software sales to this day.

Successor Technologies Are All Around Us

As you may have guessed, the whole premise of this article is a trick question. There’s not a successor to the CD. The CD served many purposes, and there’s a new technology that does each of those things better.

Turntables are still the gold standard for many serious music fans. While vinyl albums still sell fewer copies than CDs, vinyl sales have been growing for 4 consecutive years, even as CD sales have plummeted and digital purchases and streaming services have grown. The reason for this is simple: if you’re going to store your music on a medium that takes up a bunch of space and requires a special machine for playback, you may as well do it in style.

There’s no true successor technology for CDs here, because CDs pretty much did the best you can possibly do with digital audio. Sure, if you’re a mouse, you’re going to need a 200,000 Hz sampling rate to hear other mice talk, but for human beings a 44,100 Hz, 16 bit recording is about as good as it gets.

MP3 players solved the problems of portability and disc skipping in the late ‘90s. With an MP3 player, you can carry a 1,500 song library in your pocket. You can also share songs more easily with your friends. Not that we’d ever do that, because it would be illegal. Streaming media have taken this a step further. With services like Tidal, Pandora and Spotify, your collection is infinitely portable.

Think about it. To take your MP3 library with you, you need to bring your player and charger. Your streaming service username and password can be stored conveniently in your brain, and are good to log you in on any device. For commuters, students, travelers, and casual music fans, these services have replaced CDs.

The long-term storage issue has been solved by another related technology: solid-state drives. Much as solid-state technology allowed us to have MP3 players, it allowed us to build small, efficient drives with tons of storage capacity. These drives still aren’t all that common as primary hard drives, since they can fail after multiple rewrites, but they’re perfect for storing data efficiently. With an inexpensive server rack, companies can now store millions of CDs worth of data in a space the size of a broom closet. Not only are solid-state drives the successor to the CD, they’ll eventually replace traditional hard drives once the read/write issues are worked out.

We’ve already talked about Blu Ray discs for software installs. These discs hold up to 25 GB total, and there’s no reason to think there won’t be even better discs in the future, particularly with new 4K TVs and VR systems.

How long will Blu Ray remain the standard in this area? It’s hard to say, but Moore’s Law tells us that processing power doubles every 18 months. Since program size tends to parallel that, it’s not hard to imagine that we’ll be hungry for a new optical disc within 3 years, when video games start to require 2 or more Blu Ray discs.