Like many of the millions of renters across the country, this past fall I moved in with a complete stranger. In an effort to understand exactly whom I decided to share a space with, I immediately examined the six built-in shelves with my new roommate’s sizable book collection. I also inspected the large DVD collection on the tall wooden bookcase. But the final puzzle piece in the mystery of my roommate’s tastes was missing: There was no CD rack and nary a CD in sight.

Donated CDs at a Goodwill store in New York City are one place to find a growing collection. (Photo by Stephanie Marcus/CNS)

My new roommate is at a vanguard of home decor, where digitization is changing the way we decorate and the way we perceive one another. The seemingly innocuous MP3 has changed more than just how our music is formatted. The CD racks that once housed those shiny relics of the 1990s are looking for new homes — on Craigslist or eBay, where thousands of people are eagerly trying to unload their CD towers and clunky, custom-made entertainment units on to those who haven’t embraced total world digitization domination.

“One of a kind. Don’t let your records, 8 tracks and CDs be lost forever,” advertises one Craigslist seller from Yonkers, N.Y., who is trying to appeal to baby boomers to buy his 1970s-era oak and patent leather media center for $5,300. In Seattle, another seller is willing to negotiate prices on a huge, solid cherry media center and boasts of its massive capacity for storing CDs and stereo components. Their chances of finding buyers for such items are slim, considering there are zero bids for the first few pages of similar items listed for auction on eBay.

It is no secret that CD sales have suffered with the advent of downloading music — CD sales peaked in 2000, and in 2009 digital music downloads accounted for 40 percent of all music purchased, according to Nielsen Soundscan. And as our iTunes libraries grow, our CD collections are looking like someone who drank too much coffee as a kid: stunted. Suddenly having your CD collection take up valuable living space doesn’t seem so necessary and explains why a massive capacity for storing CDs just isn’t a selling point anymore.

But it’s not only the recording industry that is seeing changes from the result of digital cheerleading. As the ability to download and store movies digitally expands, DVD collections are disappearing too.

And with the need to display less, modern interior design has to adapt as well.

Custom-made cabinetry with designated space for CDs, DVDs, LPs and their required players is no longer popular, according to Toronto-based interior designer Dawn Bethune.

In addition, the trend for the past few years in living rooms has become the flat-screen TV, often mounted on the wall as the room’s focal point, without any shelving distracting viewers. In this minimalist approach, sleek and clean lines have come out on top on the design front. Home decor stores like West Elm and Ikea are showing simple cabinets or buffets with just enough compartments to hold your DVD player, PVR and Wii console.

Going digital is also changing the functions of every room in the house, according to Bethune, who has been decorating homes for nearly 30 years.

Like CDs, cookbooks are being tucked away as more people add their laptops to the list of necessary culinary tools, says Bethune. “When you look for a recipe, you aren’t looking in a recipe box or in a book, but you are Googling, ‘I have sea bass and Parmesan. What can I do with it?’”

The kitchen, she says, has become a second office. While the convection oven might have been the most high-tech piece of equipment in years past, many of her clients are adding a computer to the kitchen, used as the central space to keep families organized and scheduled.

While decor has adapted to meet technological trends, so has the way we interact within our homes. The digital shift has made for some antisocial behavior, according to Dr. Toby Israel, a designer and environmental psychologist based in Princeton, N.J.

Where music in the past was heard throughout the house, listening to it has become more of a solo activity, with people usually using a computer or iPod. “When you are relying on that type of technology, it affects the amount that people socialize,” she said. For this reason, Israel tries to design spaces that can double as private and public, as in her home office, which has two doorways that can be open and inviting.

Tangible, displayed collections also allow people to express who they are and help convey passions and interests, according to Israel. Yet shifting these collections to the virtual world offers no visual clues about matters of personal tastes to visitors or, say, a new roommate hoping you aren’t a Jonas Brothers fan.

Yet some seem to embrace the privacy digital collections offer.

Richard Carroll recently tweeted, “now that I don’t buy albums physically anymore, my CD collection is swiftly becoming a period snapshot, like my parents’ record collection.”

The 29-year-old TV producer had built up a collection of several hundred discs heavy on Britpop bands popular from the early 1990s to the start of the millennium. His collection didn’t make it in his move from England to Australia a couple of years ago, when he donated a few hundred of his “less loved” albums to charity shops, since he had them all uploaded to his iTunes library.

Carroll said he thinks it’s odd to display a collection in which the most recent albums are several years old. “I don’t want people to think I’ve stopped buying music, because I’m somehow ‘past’ it. So I guess I do display my collection less prominently now.”