Concept songs beat battery pop by going in for the long hault

Pop is eating itself – and getting fatter. The average length of a pop song in the 1960s was two minutes and 59 seconds. In this decade the average is four minutes and 26 seconds. The old Tin Pan Alley maxim “If you can’t say it in three minutes, you can’t say it at all” no longer holds as we approach the era of the “concept song”.

On Justin Timberlake’s current album, most of the songs are more than seven minutes long, and many now in the contemporary r’n’b world are going for the seven, eight or even nine-minute statement song. These figures come from a fascinating study called the Billboard Experiment which looks at how songs have differed over the decades in terms of length, tempo, artist familiarity, time signature and key/mode.

The only thing that hasn’t changed over the decades is the predominance of words such as “love”, “baby”, “heart” and “yeah” in the lyrics. But we knew that already. Artists, though, are pushing the song -length boat out in order to stand out from the banal and homogenised musical crowd. There is a certain commercially successful sound produced by a small pool of songwriters and producers that dominates the charts. There have never been so many big-selling songs all in the same tempo and the same key.

The prevalence of "battery pop" has been scientifically proven. A Spanish study – mentioned here before – analysed half-a-million pop songs from 1955 to the present day and found that today's music has fewer chords, less complex melody lines and a generally more limited "timbre palette". And it does seem that anything that sells more than a million copies has either the name Calvin Harris or David Guetta on it.

The new conventionalism is being challenged, though, by the concept song. One of the most critically acclaimed tracks of the past few years is Frank Ocean's Pyramids , which comes in just short of 10 minutes. Hailed as a Purple Rain for the iPod generation, Pyramids is epic, complex and intriguing. On My Beautiful Dark Twisted Fantasy , Kanye West was regularly hitting, and exceeding, the seven -minute mark.

On their current Shake The Habitual album, The Knife have two songs at nine minutes, one at 10 and one at 20. The current Irish number one is Daft Punk's Get Lucky , which comes in at a very long (for a chart hit) six minutes-plus.

Judging by what it has produced so far, the current vogue for long songs is a good thing . And there's a noble history to the long song. If you ignore anything ever recorded by Tangerine Dream or any of their preposterous ilk (and also ignore short-long monstrosities such as November Rain and Bohemian Rhapsody ), some of music's finest moments have come in at around the 10-minute mark.

Television's Marquee Moon (10.40), Bowie's Station To Station (10.14), The Stone Roses' Fool's Gold (9.53) and Madness's The Liberty Of Norton Folgate (10.10) are just some examples of quality, creativity and length.

It’s relatively easy – especially with today’s pre-programmed optimal pop packages – to get in and out in less than three minutes, but it takes something special to hold it together beyond the 10-minute mark without just stitching two or three disparate ideas together. In pop today, size really does matter.