It’s September 9, 1951, in Richmond, California, and Nubella Johnson has just gotten into town with her mother, her husband, and her children after a long night in the car. She’s driven all the way, eager to start her vacation with the rest of her family in Apartment K at 451 Commercial Avenue. By 12:45 a.m., the kids have finally gone to sleep, and the Johnsons sit down to record a letter to Nubella’s brother Lester on the phonograph. They lead in with some quiet and bluesy piano jazz, and then Nubella tells Lester how much she misses him. "There’s so many things I could say," she says, holding back tears, "but I just can’t get them together." Nubella tells Lester that she wishes she had sent the record sooner, before "everything went wrong." You could still do this back in the ’50s. You could still use your phonograph to record audio letters, or "recordio-grams" as they were known, on special blank recordable discs and then send them to friends or loved ones in pre-designed envelopes often stamped with slogans like "A personally recorded message for you." The recordio-gram was the last remaining trace of Edison’s original intention that the phonograph be a talking machine that could record memories, the first apparatus that could store memories in sound.

When Edison recorded himself at that breakthrough session, it wasn’t just the first time a person could listen back to his words, it was the first time the sound of those spoken words could be made to outlive the speaker. The invention of the recorded voice was the advent of the disembodied voice — the voice that bespoke the self but could be separate from it, the voice that could travel beyond the amalgam of bone, muscle, blood, and breath it once issued forth from. Indeed, in phono-obsessed writer Marcel Beyer’s remarkable 1997 novel The Karnau Tapes, the chief narrator, who works as a sound archivist for the Third Reich, spends his spare time collecting phonographically recorded sound in an effort to create a "vocal atlas" of the world. He is particularly enamored of the recorded human voice and its ability to work as a vessel of memory — a voice that embodies and transmits the history of its owner. "I shall always find it inexplicable," he marvels at one point, "that a recorded voice — just the fluttering of someone else’s vocal cords — should have such power to stir the emotions." He believes that because each moment of speech leaves a scar on the vocal cords, we are all marked by traces of our voice, our larynxes holding an unseen key to an autobiography unwittingly written over the course of our spoken lives.

Lester Johnson may never have received his sister’s voice letter, but more than half a century later it has become the first track on The Private Press, the new album of sample-based music from DJ Shadow. There’s a little of Beyer’s narrator in Shadow, who likewise lives to collect sounds and then figure out what to do with the records that these recordings have stored. In his hunt for new vocal lines and breakbeats, he presumably came across the Johnson recordio-gram the way he would any old record — just another piece of vinyl collecting dust in a thrift store, its memories waiting to be unlocked by a complete stranger. But unlike the way he tweaks Dennis Olivieri’s "I Cry in the Morning" on "Six Days" or Barry O’Brian’s "Tell Me Why the Tape Wobbles" on "Right Thing," Shadow doesn’t sample Nubella. He lets her letter to Lester play at the beginning and at the end of the album, turning one woman’s private correspondence into a conceptual frame for a beat-bolstered collage of stolen moments that retails for $17.99.

Shadow’s use of personal voice recordings is one more step in the evolution of a micro-genre that may have began with Damien Jurado’s 2000 collection Postcards and Audio Letters (Made in Mexico). Jurado’s disc focused on taped letters he’d discovered — two sides of taped correspondence between two struggling lovers and a report from a 1983 Christmas. He also included discarded answering-machine tapes on which a divorced couple fight bitterly over the safety of their child. ("I don’t care what you like," the man barks to his ex. "You can’t do jack-dick about it. That’s really stupid. Don’t fuck with my life just because it’s not up to your expectations.")

As compelling as these recordings were, Jurado simply compiled them and presented them as separate tracks on an album. Shadow uses Nubella’s letter to hint at a larger statement about the spacious post-hip-hop and neo-electro landscapes it frames. He suggests that contemporary pop music, at its core, comes from the same place as Nubella’s letter to Lester, from the unceasing desire to record our lives in our own voices — to give our memories a sound of their own.