Much has been written about Serial (no spoilers ahead) over the course of its first season, with a lot of folks arguing that it’s ushered in a new era for podcasting. (Never mind that this new era has been ushered in several times before.) The success of Serial has been pinned primarily on the compelling mystery of its true-crime story. But just as frequently, people talk about how “well-edited” and “well-produced” it is, compared to most podcasts, which makes sense, because Serial’s parent program, This American Life, is certainly among the most carefully edited and produced programs on public radio.

But I wonder if people outside the world of radio journalism realize exactly what they mean by “well-edited” and “well-produced,” why Serial sounds so different from most other podcasts. In all the discussion about podcasting this fall, I’ve haven’t heard much talk about the different kinds of podcasting — the taxonomy of podcasting, as it were. "Podcasting” is not a genre; it's a medium. There are as many different kinds of podcasts as there are kinds of TV shows. Comparing Serial to WTF with Marc Maron is like comparing The Wire to the Daily Show.

Part of this confusion comes from the fact that radio, especially public radio, has long mixed genres, sometimes even within the same show. There are pre-taped and edited interview shows like Fresh Air, live to tape discussion shows like Here and Now, variety shows like Prairie Home Companion, and news programs like All Things Considered and Marketplace.

Some of these shows blur the boundaries between genres, mixing interviews with scripted essays and documentary style reportage. But it was arguably This American Life that set the bar for using all powers of radio to tackle its weekly themes, switching mid-show from a documentary story to an essay by David Sedaris to a radio drama, perhaps set to verse, about farm animals. Part of the reason This American Life inspired a generation of young listeners to go into making radio is that Ira Glass demonstrated how powerful the medium can actually be, how many different forms it can take.

But as much as I love the ambition inherent in TAL’s variety, I’ve enjoyed it less and less over time. These days, when the show cuts to a scripted personal essay, a work of fiction, or a parable about a squirrel, it has to be really good for me to keep listening. And when I think back on the most powerful moments from the show, I always think of episodes devoted to a single subject, like the episode about the prison production of Hamlet, or Harper High School, or the two girls switched at birth.

What those episodes (and the shorter stories like them) contain is what print journalists call “reporting” and what radio journalists call “tape” (an anachronistic but persistent term that Ira Glass discussed at the recent Third Coast Audio Festival): a journalist had a question, he or she went out into the world (or through a telephone line), asked questions of real people, and came back with answers.

You could just call this “investigative journalism,” but that term tends to only be associated with uncovering crimes or scandals, whereas this kind of reporting can be employed in even the most personal of stories. One of my favorite examples from This American Life is a story Starlee Kine did about her parents' divorce. The story starts off sounding like a semi-comical personal essay about Kine’s mother (who did crazy things like forging her husband’s signature to buy a house without his permission), but it turns dramatically more emotional when Kine interviews her actual father over the phone, asking him why he didn’t divorce his wife sooner.

Starlee Kine: It's quite a mystery why you fought so hard to keep this marriage together that you guys were never happy in. Like, never. Father: Because I felt that I was primarily responsible for her unhappiness. Starlee Kine: That's not true, Dad.

This exchange has almost no resonance in print. And it would have very little resonance if Kine scripted it herself. But when you listen to the tape, you can hear the pain in her father's voice as he makes this admission, and you can hear the sadness and love in Kine’s voice as she tells him it’s not true.

This is the power of tape, and I’d argue it’s a power tape has over any other form of journalism. Print can’t convey the full texture of emotion in a conversation, and film often shines too bright a light to get into these private moments of our lives. Tape bridges the divide, capturing reality without distorting it too much, and remaining sharable in its original, organic form.

I remember one of the first radio stories I ever made, I went to chaperone a prom with my wife (a high school teacher), and I just ran the recorder all night long, interviewing, capturing sounds and scenes. When I got home, I felt like I’d returned from the forest with gnarled pieces of old wood under my arm, ready to start building my sculpture. That's what gathering tape can feel like.

What makes Serial special, for me at least, is not that it’s just a good yarn, though that certainly helps. It’s that much of the yarn is made of tape, and so many different kinds of tape: journalist interviews, police interviews, court testimony, scenes in cars and parking lots, and of course those phone calls from the Maryland Correctional Facility. The story was compelling because it felt so immediate, so real. Tape was what made it real.

There’s nothing new about this kind of reporting, and there’s nothing new about using great tape to keep listeners on the edge of their seats. What’s new is that the medium of podcasting let Serial go deeper, for longer, to gather and sift and edit together so much tape so compellingly that millions of people kept coming back week after week to the same story.

The podcasts I found most exciting in 2014 were shows like HowSound, Re:Sound, Death, Sex & Money, The Longest Shortest Time and Radiotopia shows like Strangers, Love + Radio, and Radio Diaries: shows that feature the voices and lives of the un-famous, endlessly interesting real people in our world. This is why, when I recently decided to get back into radio and start my own podcast, I set out to interview people from all walks of life. I hope Serial inspires more podcasters to make shows like this, with less talk and more tape.