MICHELE NORRIS, host:
(Soundbite of "Single Ladies (Put a Ring on it)" by Beyonce)
Ms. BEYONCE KNOWLES: (Singing) All the single ladies. All the single ladies. All the single ladies. All the single ladies...
NORRIS: We're going to go a little scientific now about pop music. One man has a theory about a possible correlation between volatility on the trading floor and what's hot on the dance floor. Phil Maymin is assistant professor of finance and risk engineering at New York University. He's analyzed songs from the Billboard Hot 100 using computer software. And what he's found involves beat variance - songs with a more steady beat or a low beat variance seem to be hot when the market is volatile, and vice versa. Songs with high beat variance are popular when the market is calm. He recently explained his theory to us.
Dr. PHIL MAYMIN (Assistant Professor of Finance and Risk Engineering, New York University): I think the key linking idea is mood. The mood of the people is probably influenced by the market. If you think market volatility is high, you might choose to then listen to what kind of music? More volatile music or less volatile music? What would you listen to?
NORRIS: I would think less volatile. You'd want to calm down.
Dr. MAYMIN: And that seems to be what happens. People tend to want to calm down. People use music in a sense as an escape.
NORRIS: We need to listen to some music to explain this concept called beat variance. And so before we go on, please define that term for us. What exactly is beat variance?
Dr. MAYMIN: Variance is just a measure of how far a number deviates from its average. So a low beat variance song does not deviate from its average beat very much. It doesn't matter whether the average beat is slow or fast, but it's a constant boom, boom, boom, boom. Whatever it is, that's a low beat variance song. Meanwhile, a high beat variance song probably has changes in tempo and beat. Maybe it starts off slow and then it gets really fast for a while and then it comes back slow again. That would be a high beat variance song.
NORRIS: So, why don't we do a little of bit of show and tell. And since we're on the radio, maybe a little hear and talk. Let's listen to some music. First a song with very low beat variance. This is a song that's actually at the top of the charts right now by Lady Gaga. It's called "Just Dance."
(Soundbite of song "Just Dance")
LADY GAGA: (Singing) Red one, convict, ga-ga.
NORRIS: A fairly consistent beat there.
Dr. MAYMIN: Yeah, you can really hear it, right?
(Soundbite of "Just Dance" by Lady Gaga)
LADY GAGA: (Singing) I've had a little bit too much, much. All of the people stop to rush, stop to rush by.
NORRIS: If you're doing that disco head bopper thing, I could see how you'd be almost like a metronome.
Dr. MAYMIN: Yeah, that's exactly what I'm doing.
NORRIS: Those "Saturday Night Live" guys.
Dr. MAYMIN: Exactly.
(Soundbite of laughter)
(Soundbite of song "Just Dance")
LADY GAGA: (Singing) Keep it cool, what's the name of this club? I can't remember, but it's all right, all right. Just dance, gonna be OK.
Dr. MAYMIN: And you can't do that to a more complex song. These songs that you nod your head to it, there's something physiological about that. It really does calm you down. And it can only happen with a low beat variance song.
NORRIS: Now, we have an example of a song with a very high beat variance. This is from an artist John Legend. The song "Ordinary People."
(Soundbite of song "Ordinary People")
Mr. JOHN LEGEND: (Singing) Girl, I'm in love with you. This ain't the honeymoon, Past the infatuation phase.
Dr. MAYMIN: If you're trying to do the, as you said, the "Saturday Night Live" head bopping thing, it's much harder to do to "Ordinary People." There are points when you kind of get it, but then it changes.
(Soundbite of song "Ordinary People")
Mr. JOHN LEGEND: (Singing) And though love sometimes hurts, I still put you first and will make this thing work, But I think we should take it slow. We're just ordinary people.
Dr. MAYMIN: I find it engages the mind a lot more. It's more intellectually draining, I think, to listen to such a song.
NORRIS: So, does this theory hold up over time? If you - I know that the software is new. But if you went back and looked at the Billboard 100 and mapped that against highs and lows in the market, what will we find?
Dr. MAYMIN: That's exactly what I did. I analyzed all 5,000 top 100 songs over 50 years from 1958 through 2007. For each of the 100 songs in each year, I calculated its beat variance using the software. Then I take the average for all of the songs for that year to get a sense of what was the average sort of beat variance that people were exposed to in popular music for that year. And that sequence of numbers we look at the correlation between that and the market volatility of the appropriate time period, and it turns out that the relationship persists for 50 years.
NORRIS: Now, we talked about pop music, but I'm wondering if this same theory applies to other genres - punk music, jazz, country?
Dr. MAYMIN: Those are wonderful questions. Obviously this is - you know, that'll require further research. The reason I started with pop music was by definition it's popular. It's what people are listening to. Or at least it's the best proxy that I could find for what people are actually listening to.
NORRIS: So when you go out and buy music or you decide what you're going to download on your iPod, are you cognizant of this research?
Dr. MAYMIN: I am now. But on the other hand, a lot of the music that I listen to is driven by my baby daughter. She likes, you know, "Wizard of Oz" music and you know, "Supercalifragilisticexpialidocious," so I don't really have a choice. I like listening to what she likes listening to.
NORRIS: "Supercalifragilisticexpialidocious" - high variance or low variance?
Dr. MAYMIN: Actually, I didn't analyze it. I'm not sure.
NORRIS: Get to work.
Dr. MAYMIN: I will.
NORRIS: All right. Thank you very much.
Dr. MAYMIN: Thank you.
NORRIS: Phil Maymin is an assistant professor of finance and risk engineering at the Polytechnic Institute at New York University. And Professor Maymin, since we here at NPR report the news, and since this has been a year of high volatility, we might as well go out with a song that, at least according to you and your research, seems to reflect the market. So let's cue Beyonce with "Single Ladies"
(Soundbite of song "Single Ladies")
Ms. BEYONCE KNOWLES: (Singing) If you liked it then you should have put a ring on it. If you liked it then you shoulda put a ring on it. Don't be mad once you see that he want it. If you liked it then you shoulda put a ring on it. Wo oh ooh.
NORRIS: You're listening to All Things Considered from NPR News.