Popular music is shrinking. From 2013 to 2018, the average song on the Billboard Hot 100 fell from 3 minutes and 50 seconds to about 3 minutes and 30 seconds. Six percent of hit songs were 2 minutes 30 seconds or shorter in 2018, up from just 1% five years before.

Take Kendrick Lamar, one of the world’s most popular musicians right now.

The average track length on Lamar’s breakout 2013 album good kid, m.A.A.d city is 5 minutes 37 seconds. All are 3 minutes 30 seconds or longer. On Lamar’s most recent album DAMN., the average song is 3 minutes and 57 seconds. DAMN. won the Pulitzer Prize for music, going to show that this trend isn’t necessarily lowering the quality of music.

It’s not just Lamar. The trend can be seen in albums of music’s biggest stars, like the rapper and singer Drake, perhaps pop music’s most dominant force.

Unlike Lamar, Drake’s albums are getting longer as his songs get shorter.

Kanye West’s tracks are also getting dramatically shorter. His 2016 album The Life of Pablo had eight tracks that were less than three minutes long, while on 2010’s My Beautiful Dark Twisted Fantasy there were only two.

The rappers Nicki Minaj’s and J. Cole’s albums follow the trend as well.

It’s not just popular rappers. Country songs are shrinking too. Eric Church and Jason Aldean have been nearly constant with the number of song on each of their albums, but their songs keep getting shorter and shorter.

Why are songs getting so much shorter? Streaming is one the most likely culprits.

Payments from music streaming services like Spotify and Apple Music made up 75% all US music revenues in 2018 (pdf), compared to just 21% in 2013. Streaming services pay music rights holders per play. Spotify doesn’t say the exact amount it pays artists for each stream, but reports suggest it is somewhere between $0.004 and $0.008. Every song gets paid the same. Kanye West’s 2010 five-minute opus “All Of the Lights” gets the same payment as West’s two-minute long 2018 hit “I Love it”.

“[T]here has never been this kind of financial incentive to make shorter songs,” tweeted Mark Richardson, the former editor of the music criticism site Pitchfork. Stuffing more diminutive songs into an album is simply more remunerative than having a bunch of long ones.

Still, it’s hard to pinpoint exactly how much streaming has contributed to the recent shortening of songs. The length of pop songs had already been falling through the 1990s, before accelerating in recent years. Some music industry observers blame shortening attention spans—but there isn’t much rigorous evidence that our ability to focus has changed (paywall). Others believe that shorter songs may be a result of more consumer choice—songs need to be more compact and catchy to stand out in the crowd.

Then again, music has always changed with technology. Early phonographs could only hold about two to three minutes of music, so as a result, that was the length of the typical song from the 1920 to 1950s. The introduction of the LP record, and then the tape and the CD, made it possible to have longer songs, with each medium’s larger storage capacity. Now in the age of streaming, technology and economics seem to be sending us back towards brevity.