A combination effort of streaming incentives and whatever random short videos the kids are making these days has driven the average song length in the pop charts to recent lows, and of course just about anyone older than unspecified target demographic might be complaining about it. I tend to view it as a blessing for songs I don’t like, because it’s at least on to the next thing quicker, and given modern songs in my usual opinions, it’s hit or miss. Song structure can get as short as chorus-verse-chorus, not even much of a bridge or interlude anywhere. For more complex songs they just might shorten each part to hit the new sweet spot length of under 3 minutes, sometimes even below 2.
Having grown up listening to oldies, which in the 1990s tended to span the 50s and 60s for the most part, I absolutely know that typical songs were shorter around those decades, and can even dig up research to back that up, such as measuring the average length of licensed songs in Bethesda Fallout games. Whether or not those songs are better is subjective, but I tend to like them more. And I’m also certain that it was also industry forces that drove songs to be as short as they were on the charts, and likewise what eventually led to songs being longer for some time.
Back in that oldies time, songs often came on these things called records, which existed long before the nostalgic angle they sell modern albums on now. Sometime records came with one song on them, and those might be smaller so they could fit in a jukebox, which is some kind of big machine that has a stack of these smaller records inside that can be played on demand. Something like a giant iPod, or more recently, a more limited physical version of Spotify that requires a small fee per song of a few cents. Not quite like a Redbox since in those you actually take out the discs to play at home, discs typically stayed in jukeboxes and played there until they were swapped out by whoever managed it. Alternatively, a record could be a bit larger but just spin around faster for likely better sound quality. The rates and sizes the industry eventually decided on for these came out to determine a maximum playback time of around 3-5 minutes or so, depending. Therefore, to move a single song, it had to fit on one of these and therefore match the length. In an economic sense, it would make more sense to have songs under 3 minutes to distribute on more formats. And given the whole motivator of the music industry is to sell music, they want songs that they can sell.
All song lengths aren’t explicitly determined by the industry though, there are still artistic angles at play, and maybe a song is just going to be really short by choice. However, a big factor is what gets out as a single, and with everything the industry is composed of, is length. There are also other parts that involve dissecting psychological profiles and crossing those with song structure for maximum marketability, but if the signing label wants a single, they could outright demand one be produced and slapped on the latest album. Apparently that’s part of how Korn’s “Y’All Want a Single” came about, and weirdly enough, that ended up becoming a single anyway, radio edit and everything.
With radio edits, songs that may be just a little too not single-friendly for some contexts can be altered further. Maybe some extended parts are cut out like solos or bridges or interludes or whatnot, and this even extends backwards to long-played songs now getting cut down on variety stations and the like. Maybe a song that normally includes a rapper just has that whole part removed, either the song just ends before that part, or they put in some made-up interlude using existing material. Even with the increasingly common occurrence of having rappers just show up on songs, some radio stations just don’t want to deal with that by any means for some reason, which could either be systematic or someone did a controversy for all I know. Some songs do get released with two or more versions in case of personal preference or a later remix, but editing a song that was initially made with a guest rapper to not have one just seems weird. Katy Perry’s “Dark Horse” is a big example of this, I’ve heard multiple versions of this song, and several remove Juicy J’s verse, yet not always from the intro.
Even with radio edits, sometimes the radio station may edit the song further. Like with TBS and A Christmas Story, songs may get increasingly sped up to either fit more music in between commercial blocks or more likely to play more commercials while sticking to the same rough amount of songs. They might even get pitch shifted, intentional or a side effect of the speed up. If intentional, it’s been cited somewhere that it’s meant to make the songs sound “happier”, which can come off really weird for songs that aren’t in a major key or otherwise downbeat, or aren’t even mainstream pop.
Generally, shorter singles have been around for about as long as the music industry has been, just that they’re back to getting even shorter again. As mentioned at the top, it seems to be streaming incentives mixing with trying to get short form video creation to latch onto songs with a short and easy hook for whatever reason, often for some random dance “challenge” or otherwise. If songs are paid out by play instead of by minute, then having a shorter song loop more is more lucrative to the label. Therefore, something like Napalm Death’s “You Suffer” would be ideal if they could convince pop artists to produce more of that. Of course that would also annihilate the novelty of doing so and possibly crash a small part of the industry.
There is also the factor of people possibly being trained by the industry on what to like, because chances are someone’s major exposure to music includes a fair bit of radio, whether broadcast or online. If someone never hears anything outside of that, they’ll probably be fine just sticking to it. If songs trend shorter, the person may be fine with shorter songs, as singles are typically short anyway. There was once the weird concept experimental album called The People’s Choice: Music consisting of two songs, one “wanted” and one “unwanted”. The “wanted” song is roughly 5 minutes and is a weird mix of love songs and other common desired elements of the time the poll was taken, in the mid-1990s. The “unwanted” song is an even weirder mix of rapping opera, children singing about Wal-Mart, and cowboy themes, and is over four times as long. Somehow, probably due to the whole novelty aspect, the “unwanted” song proved more popular. The whole thing is a weird scientifically approached comedy anyway, but to consider for a moment what people actually want in a song, when asked about it, could line up at least a fair bit with common elements in pop songs around that time, I wonder if that’s preferences people found looking at music itself or heard on the radio.