And the Grammy Goes to — a Mathematician?

Mathematician Kevin Short shared in a Grammy award recently for his work in restoring "The Live Wire: Woody Guthrie in Performance 1949." Short's work on compression and chaos was used to help adjust the speed and timing in the original recording, improving pitch and clarity.

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JOE PALCA, host:

From NPR News, this is TALK OF THE NATION: SCIENCE FRIDAY. I'm Joe Palca.

Coming up, we'll talk about a new report on genetic variability in humans. But now, SCIENCE FRIDAY goes to the Grammys. Well, why? Here's the story.

It turns out that this year's - one of these year's Grammy Award-winning albums was called "The Live Wire." It's an amateur recording of a 1949 Woody Guthrie concert in Newark, New Jersey. It's the only known recording of a live performance by the late folk singer. And it was made on an obsolete piece of equipment called a wire recorder.

A team of engineers took the old analogue recording and converted it to digital. And then a math professor from the University of New Hampshire did some mathematical repair work of the digital version to make it sound better. It was so good, in fact, that it earned them the 2008 Grammy for Best Historical Album.

Joining me now to talk about this audio restoration is Kevin Short. He's a professor of mathematics at the University of New Hampshire in Durham, and is part of the team that won the 2008 Grammy for Best Historical Album. He joins me today by phone from his office in Durham, New Hampshire. Congratulations on the Grammy, and welcome to the program, Dr. Short.

Dr. KEVIN SHORT (Professor of Mathematics, University of New Hampshire, Durham): Thank you very much. Thanks for having me.

PALCA: And if you'd like to join the discussion, give us a call. Our number is 800-989-8255, that's 800-989-TALK. And if you want more information about what we're talking about this hour, go to our Web site, www.sciencefriday.com where you'll find links to our topic. And you can also join in this discussion by going to "Second Life," and listening in - there's a group of people gathering on Science Friday Island and you can join them and chime in from there, if you wish.

So, Dr. Short, I mean, I guess what - I know that this project involve many people and I wonder if you'd set the stage for us about what happened before you got involved and then we'll take it through when you got involved. So how did this all get started, this restoration project?

Dr. SHORT: Well, I guess, it started back in 1949 when they recorded the original concert.

PALCA: Wow. And maybe - can you tell me what a wire recorder is, because I think I've heard of them, but I can't really picture something.

Dr. SHORT: That's pretty much the best reaction we get.

(Soundbite of laughter)

Dr. SHORT: It turns out that just after World War II, they came out with these wire recorders that would take the kind of wire you used to find in a hardware store, and they would run it over a magnetized head and they could record.

PALCA: Oh.

Dr. SHORT: They're primarily used for dictation machines. But, you know, some musicians got hold of them and started recording some things. But by 1950, it had pretty much been replaced by tape. I guess tape came in around 1950. And so they're fairly obscure. But it really is the kind of wire that it looks just like the wire you would have gotten on a hardware store.

PALCA: So you basically - you've got a spool of wire and you record onto it as opposed to something thin like magnetic tape. So this recording was made by a guy who had one of these machines, and what happened to the (unintelligible) for 50 years?

Dr. SHORT: Well, his name is Paul Braverman, and he was a student - I guess -at Rutgers, and went over to the concert in Newark. He knew that Woody Guthrie was an important in folk music and also, you know, political positions of things. So he went and recorded it and afterwards sort of decided, you know, this could be interesting someday to somebody. So instead of throwing it out or recording over it, he put it in a box and stuck in the back of a closet, and probably forgot about it.

(Soundbite of laughter)

PALCA: Sounds familiar somehow.

Dr. SHORT: Yeah. So apparently, what - it gets pretty interesting. He was moving at some point and, you know, sort of cleaning out the house. And this is right after I guess September 11th, he boxed it up and sent it into the Woody Guthrie Foundation.

PALCA: So he found it, knew what it was, and mailed it to the Guthrie Foundation, but it came on right after 9/11.

Dr. SHORT: That's right. So getting a box full of heavy wire was a little bit scary at that time.

PALCA: Yeah, I'm sure. But anyway, they - eventually, they took it out and what did they do with it?

Dr. SHORT: Well, at first, I think they didn't know what to make of it and then sort of started asking around and realized that it actually was a - likely to be a recording on wire. And, you know, you can't exactly run down to the corner radio shack and get a wire recorded. So they had to track down what to do with it. And even the old wire recorders wouldn't be very high quality. They were not fidelity things. But a guy named Art Shifrin over in Queens, New York had converted a tape player so that it could read the wires.

PALCA: Uh-huh.

Dr. SHORT: And so they worked with him. And at that point, I think, they brought in the guys from the Magic Shop - Steve Rosenthal, who's also in the group and…

PALCA: The Magic Shop - what's that?

Dr. SHORT: It's a studio in New York.

PALCA: Oh, I got it. Okay.

Dr. SHORT: They've actually been well recognized for their restoration work. And they also - after - I guess they did a first pass on it and realized that wire is not like modern recording, so there's a lot of wobble and things in the wire recording. And so they brought in Jamie Howarth from Plangent Processes, and Jamie is a, you know, built his company around how you fix the timing in these things so that you can make it like - more like a modern recording.

PALCA: I see. Okay. So - and I - as I read some of the descriptions, it was a bit of a nightmare getting this stuff off the wire and onto a digitized…

Dr. SHORT: Yeah.

PALCA: But they did it.

Dr. SHORT: That's right. I mean, I - being the mathematician, I get to sit back in the office and just wait until someone sends me a digital file.

PALCA: Yeah.

Dr. SHORT: but - and I heard this is like a 36-hour effort. I think Jamie held his finger against the wire to keep the tension. So he's now a human tensioning device.

PALCA: Oh.

Dr. SHORT: And one of the other guys in the magic shop - I think it was Bryan - he - the wire would break, because it's got to be really tense and now, remember this is 50 or 60-year-old wire.

PALCA: Yeah.

Dr. SHORT: So when they keep it under tension, then it snaps. And when it snaps, it snarls. And so he had to sit and pull these things out painstakingly so that, you know, you wouldn't lose Woody, because if you lose any of the wire, you'll lose this, you know, historical treasure.

PALCA: Right. Right. So - okay. So one day the file comes to you. I presume - how did they identify you as someone who they'd want to work with?

Dr. SHORT: Well, actually, I had met up with Jamie Howarth earlier. I had, in the past, started a music compression company. And I had developed some technology to shrink music files down small enough so that you could send up to cell phones. So - like the company I started actually runs the Sprint Music Store.

PALCA: Huh.

Dr. SHORT: And so, I had been going to audio engineering society conference meetings and publishing papers on sort of how you analyze the audio because I was really sort of building mathematical models of what was going on at these audio signals. Now, originally, I was working on nice things that came off of CDs, but Jamie heard about my work and contacted me - actually about six months before the project came down the pipe for the Woody Guthrie stuff.

PALCA: I got it. Okay. So now, you've got this file, and what you do with it? How much can you fix it after you get your hands on it?

Dr. SHORT: Well, the biggest difficulty with old recordings is that the motors weren't as good, the controls weren't as good. So we've come to expect sort of perfection in recordings now that we have CDs, and when they try to take these old recordings and convert them to CD, it's very much more unforgiving. And you can hear all the imperfections from the original recording.

So sort of the inspiration that Jamie had from his background in recording studios was that a lot of these problems were probably caused by, you know, a ball bearing in the tape machine starting to wear a little bit…

PALCA: Right.

Dr. SHORT: …or things like that. And he decided to go looking on these tapes to try to find a signal that would tell them whether the original tape machine was speeding up or slowing down. And that was the cool thing that he found that, you know, normally, CDs are sampled 44,100 samples per second.

PALCA: All right.

Dr. SHORT: And so he got some special equipment so that he could digitize things like 384,000 samples a second.

PALCA: Whoa. So that's a lot more.

Dr. SHORT: That's right. And with what they were able to find was certain signals that are actually just sort of like in the magnetic residual on the tapes that would show what the tape machine was doing, whether it was speeding up or slowing down.

PALCA: Now, we have two clips here that we have. And are you - these are before and after, I understand. These are the before - the first one was presumably the way it sounded when you first got it, is that - or do you know which the tape that we have in hand?

Dr. SHORT: Yeah. I mean, it's a little difficult unless you sort of have headphones on to tell for sure what the improvements and things are. But…

PALCA: Well, hang on one second. Because we were originally going to do this - we were going to think about playing them back to back, but they are - we're thinking also about playing them simultaneously and going back and forth between them. So why don't we do it the way - to so it simultaneously and go back to back. I know that's not what we originally decided on. But maybe I can just call for it to go one or the other, and you can help us.

All right. Now, we're set up to do that. So we'll start with the original and we'll hear a couple of seconds of that, and then we'll flip to the other one, okay?

Dr. SHORT: Sure.

PALCA: Here we go.

(Soundbite of music)

Mr. WOODY GUTHRIE (Singer): (Singing) Most likely, it's not your fault…

PALCA: And now, change.

(Soundbite of music)

Mr. GUTHRIE: (Singing) It's like (unintelligible). Be mine…

PALCA: Now, switch back.

(Soundbite of music)

Mr. GUTHRIE: (Singing) (Unintelligible).

PALCA: And that's back to the new one. So what are we hearing? I mean, I'm hearing a little hiss; I've got headphones on. But I suspect that someone with a car small car stereo isn't hearing all that much.

Dr. SHORT: Well, it's partly because you're in the car. But one of the things is that there's a degree of twanginess to the original. And this isn't even one of the bad sections. But there's a degree of twanginess so that there's a wobble in the sound. There is a lot of background noise as well. And the - there's a lack of precision in, like, the attack of the notes, the strumming of the guitar. Normally, when someone strums a guitar string, you hear a real snap.

PALCA: Mm-hmm.

Dr. SHORT: And those kind of things get smeared out when there's timing - there are timing errors and things like that. So when you listen to the second one, particularly if you, you know, have it right there, you know, coming out of speakers or in headphones, you'll hear that there's much greater precision in the attack. In the Woody Guthrie stuff, we actually had cases where - at least I did, I couldn't understand the lyrics at all.

PALCA: Uh-huh.

Dr. SHORT: And there were sections were there are actually conversations between Woody and his wife Marjorie. And he was family stories and I was misinterpreting them completely.

PALCA: Wow.

Dr. SHORT: Sort of the like the - when you're - oh, (unintelligible) I would use when my son overhears every fifth word of the conversation and jumps to a completely wrong conclusion.

PALCA: Right. Right. But what I want to get to is, there is mathematical description or characterize mathematically what it means to have a clear attack from a guitar.

Dr. SHORT: Oh, sure.

PALCA: Oh, okay.

Dr. SHORT: So what it comes down to is we find and isolate that signal that tells us whether the original recording device was speeding up or slowing down. And we then look at the mathematics say, okay, this is what they measured on the tape, but if that was the result of speeding up and slowing down, we put it back to the original form.

PALCA: Uh-huh. Uh-huh.

Dr. SHORT: Now, the best example I can give you is probably something that people who have been using car stereos at least for 20 years would know. And that's when you have a favorite tape sticking in the car stereo and it gets eaten.

PALCA: Yes.

Dr. SHORT: Right? So…

PALCA: Usually it's the one that your child has been screaming for for the last six hours.

Dr. SHORT: That's right. Or it's your favorite…

PALCA: Or it's your favorite, yeah.

Dr. SHORT: …played at the most. Right?

PALCA: Yup.

Dr. SHORT: And so you take it out and you desperately try to save it, so you just stick a pencil in one end and try to tighten it up, or stick your finger and tighten it all up. In the course of doing that, it usually gets kinked, it gets stretched out in different places, sometimes it gets put on to the spool not as tightly as in other places. And when you put that back - if you've experienced this - most people probably remember that the pitch goes down and up and down. Usually you hope that's just a small section and you can get back to the good stuff.

But when the tape is stretched, it totally distorts the music. And that's what we had in the Woody Guthrie tapes. It was just distorted almost everywhere to some extent, and it made it sound like, you know, Woody wasn't singing on pitch and things like that. So when we fixed it, that was all stabilized, and suddenly you felt like you were, you know, part of the performance again.

PALCA: Wow. We're talking with Kevin Short. He's one of the winners of the 2008 Grammy for Best Historical Album. But his day job is professor of mathematics at the University of New Hampshire in Durham.

I'm Joe Palca, and this is TALK OF THE NATION from NPR News.

Let's take a call now. And I guess everybody's been listening - I just think this is amazing. But let's listen to what - let's hear what our listeners have to say, and go to Cliff(ph) in San Leandro, California. Welcome to the program.

CLIFF (Caller): Thank you very much. Now, I work for Ampex 50 years ago…

PALCA: Uh-huh.

CLIFF: …and the pioneer in tape recorders. And prior to that time, tape recorders have proceeded by wire recorders which I believe were developed in Demark in 1910, and the Germans took it over and used it in World War II. Anyway, my question for your guest is, does his system of the storing - the historic recordings, does he have software that would apply to old 78s makeups.

PALCA: So, does it go straight from 78 to digital and then do repair on that file?

CLIFF: Yes.

PALCA: Yeah.

Dr. SHORT: That's exactly right. In fact, the technology - that's a nice thing about doing it in sort of a mathematical framework. The technology will work on any recording that has, you know, reasonable distortions that we can handle. And so we've applied it to 78s, we've applied it to, now, wire recordings, we've applied it to tapes from, you know, the great groups of the '60s and '70s. And so it seems to apply in all cases.

I should also mention that Ampex won a special award at the Grammys, and - for the development of the tape machine that sort of introduced high-fidelity recordings. And I was able to meet some of the engineers who were responsible for that. So it was sort of a nice coincidence.

PALCA: All right. Thanks Cliff. Thanks for your call. Let's take one more call now and go to Bryan(ph). Bryan in Menlo Park, California, down the road.

BRYAN (Caller): Yes, hello. Thanks for letting to be on.

PALCA: Sure.

BRYAN: I was listening to he excerpts that you alternated back and forth between the original recording and the digitally cleaned up one.

PALCA: Uh-huh.

BRYAN: And I prefer - you know, I didn't hear enough long excerpts to detect serious fluctuations of pitch, but I like the original sound better because it has more atmosphere to it.

PALCA: Huh.

BRYAN: It has the feeling of actually being at the concert, whereas the digitally cleaned up sounded kind of cold and sterile as if I were in a studio somewhere.

PALCA: Huh.

BRYAN: There's a local station who plays big band music and sometimes they play digitally cleaned up versions of the recordings from the '20s and '30s. And cleaning that does involving, because they don't - again, they don't have that atmosphere or that feeling and they're not giving the sound that the original audience heard.

PALCA: Well, that's…

BRYAN: I think the original - and I almost had a visual sense of being outdoor at a concert, even so than I was in this rather clinical studio.

PALCA: Well…

Dr. SHORT: I think…

PALCA: …Bryan - that's an interesting point. Thank you. Kevin Short, what do you make of that?

Dr. SHORT: Well, I think - I mean, they're listening to something that's coming over a radio so they're not really quite experiencing it the way they should. And what we're doing is not really the attempt to do digital clean-up. It's quite different. What we're doing is we're correcting the timing so that it's equivalent to what it should have been. And so we're correcting an original recording difference. So it's not the same thing as trying to change the sound effect; this is done for archival purposes.

PALCA: Right. But the tape - you can clearly hear that there's a hissing that's been taken out between the original version and the repaired version.

Dr. SHORT: Oh, sure. It's not - I mean, there's a warmth to hiss and there's a - this is very similar to one of the things people talked about when digital recordings were originally introduced. There was a warmth to, you know, old vinyl, but a lot of that warmth had to do with background noise.

PALCA: Right.

Dr. SHORT: And so, you know, the history wants to move away from that.

PALCA: Right. Right. You know, as a psychologist, I'm always tempted to - it's what we think of as warm and friendly. If we happen to grow up on vinyl, that sounds warm and friendly. It is - the new generation is going to think digital has got something in - whatever replaces it will be the warm and friendly.

Dr. SHORT: Yeah, that's true.

PALCA: But anyway, that's our favorite pastime. So thanks very much for joining me today.

Dr. SHORT: Good talking to you. Thanks for having me.

PALCA: Kevin Short, congratulations again. He's a 2008 Grammy winner for Best Historical Album and professor of mathematics at the University of New Hampshire.

We have to take a short break. But when we come back, we'll be talking about human diversity as measured by DNA. So stay with us.

This is TALK OF THE NATION from NPR News.

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