Has music streaming killed the instrumental intro?

Intros that averaged more than 20 seconds in the mid-80s are now only about 5 seconds long, the study found.

Depending on what rocks your musical world, the popularity of streaming services might be to thank or to curse for a move away from the instrumental intro, said Hubert Léveillé Gauvin, a doctoral student in music theory at The Ohio State University. His study appears in the journal Musicae Scientiae.

Léveillé Gauvin spent a couple months listening to and analyzing songs that hit the top 10 from 1986 to 2015 and found a dramatic shift away from long intros. He also documented a marked increase in tempo.

And Léveillé Gauvin discovered that singers of the most recent successful songs hardly waste any time before mentioning the song title in the lyrics. Another change he found: Song names today are shorter than they used to be -- often just a single word.

This evolution is likely driven by what Léveillé Gauvin calls the "attention economy" of modern-day pop. And that means that artists get to the musical point more quickly in the interest of grabbing a fickle listening audience, many of whom tune in on Spotify, Pandora and other skippable services.

"It's survival-of-the-fittest: Songs that manage to grab and sustain listeners' attention get played and others get skipped. There's always another song," Léveillé Gauvin said. "If people can skip so easily and at no cost, you have to do something to grab their attention."

Rather than looking for direct income on streaming services, artists are looking for something else -to drive listeners to their concerts or to other products they sell, he said.

"Artists and producers are shifting from having their songs as cultural products to having their songs as advertisements for themselves. Your product isn't necessarily your song, it's your personal brand," Léveillé Gauvin said.

"We're operating in an 'attention economy,' and attention is scarce and valuable."

Léveillé Gauvin measured the tempo of 303 top-10 singles and found a clear trend toward faster-paced pop music in the last three decades. The average tempo increased roughly 8 percent. He compared the number of words in song titles and found more and more "one-word wonders" as the years passed.

When he analyzed how long it took for the lyrics to start, Léveillé Gauvin found that intros lasting an average of more than 20 seconds in the mid-80s have given way to intros that average 5 seconds today. And once the lyrics started, it took less time (by about 18 percent) for the first "hook," which he defined as the song's title.

"The really striking thing was the disappearance of the intro," he said. "There was a 78 percent drop. That's insane, but it makes sense. The voice is one of the most attention-grabbing things there is in music."

To see the difference, look to 1987's "Nothing's Gonna Stop Us Now" by Starship and compare it to Maroon 5's 2015 pop hit "Sugar."

Starship takes about 22 seconds to reach the first lyrics of its mid-tempo song and doesn't get to the hook until after Grace Slick's voice enters the duet that Mickey Thomas started. The listener has heard well over a minute of music before learning that Starship will not be stopped.

"It's also super 80s," Léveillé Gauvin said.

Maroon 5, in contrast, gets to the point quickly in its one-word-titled up-tempo hit. The intro is half as long as Starship's and Adam Levine is singing the hook "Sugar" within 40 seconds.

There are exceptions to the trend. Take Gotye's "Somebody That I Used To Know." The 2012 earworm has a title almost three times longer than other chart toppers that same year. Its 20-second instrumental introduction was four times longer than average. And a listener waits two full minutes before the hook.

A fifth measure didn't reveal any scientifically significant changes during the 30 years of music. Léveillé Gauvin thought it was possible that today's songs would include more self-focused lyrics, but he did not see a pattern.

In a second study, Léveillé Gauvin evaluated data provided by Spotify to see if popular songs by a given artist were more likely to fit the attention-grabbing trend than less-popular songs released by the same artist. For the study, he looked at the most-streamed songs on Spotify and compared those to the least-streamed songs by the same artist.

He found no evidence of the "attention economy" hypothesis in that study.

Music continually evolves, driven by a variety of factors, and there's no way to explain away all the changes Léveillé Gauvin saw based on streaming services and the "skip" button alone, he said.

But he believes they are certainly contributing.

"If you look back historically, technological changes have likely shaped the way people compose and listen to music for a long time," he said, adding that the compact disc brought along an ease of skipping that was leaps and bounds ahead of vinyl or cassette tapes.

So, is this attention-driven shift a bad thing for pop music?

"It's very easy to see this in a cynical way. It's not necessarily a negative thing; it's just the nature of the beast," Léveillé Gauvin said.