NB: If you’re not interested in bands like Pixies, Radiohead and the Dismemberment Plan, you might want to give this a miss.

Back when I was still a freshling undergraduate, a friend introduced me to the Pixies’ seminal 1989 album, Doolittle. I remember I was hanging in my room being awed by the track Gouge Away, a ferocious take on the biblical Sampson and Delilah story, when a realisation hit me like a slap in the face: the song didn’t use a 4-bar progression. It used 5.

The discovery that such a thing was possible – and felt so good – was on par with the fateful day back in high school when I accidentally discovered my penis’ second function.

A quick aside for any non-musically savvy readers may be in order. Many, many songs are written in ‘4/4’, meaning you can count 1 to 4 over and over again to the rhythm. These 4 beats together make up a bar, and bars are usually found in groups of 4. So, 4 bars of 4 beats each, repeat ad nauseum.

This structure is so ubiquitous in many musical genres (rock, dance, pop, country, hip hop etc) that for many listeners – and many musicians – it’s a given, a fundamental constant of music which needn’t even be considered. All songs are written with different tempos, instrumentations, melodies and harmonies, but for the great majority of popular music the time signature is fixed: 4 beats per bar, 4 bars grouped together. By analogy, you could make an infinite number of soups by combining different ingredients, but the final product is pretty much always served in a bowl. But what if, just for once, you drank your soup from… a boot?

It wasn’t long after the Gouge Away discovery that I realised that, in fact, the entire of Doolittle was as riddled with weird rhythmic choices as Madame Chat is with fleas.

The tracks Tame and Hey both use a 3 bar pattern in the chorus. The excision of the expected 4th bar creates a frantic rushed effect, like the repeats of the chorus are crashing down upon each other. Wave of Mutilation also does this, except with only 2 beats per bar, while There Goes my Gun uses 6 beats per bar. La La Love You uses a 2 ½ bar pattern (!), and Crackity Jones and Dead are so all over the place that I can’t even figure them out. Silver uses a 3/4 time signature, which is actually not uncommon in classical music, but unusually it puts bars in groups of 7.

Pixies did some pretty original things for a rock group, but they were still essentially fiddling with the 4 bars of 4/4 format, adding or subtracting a bar, maybe throwing in an extra 2 beats here and there.

Then there was fucking Radiohead. Citing the Pixies as a major influence, they took this rhythmic tomfoolery to the next level in their timeless 1997 OK Computer.

Remember the indefinable murk of Paranoid Android? Well, that ambiance is partly achieved through the song using a 12 bar pattern – much harder to wrap your head around than the usual 4 bars. Lucky uses a 14 bar progression, and there’s a 10 bar pattern at the beginning of Airbag; these serve the same purpose of throwing the listener off the trail. Paranoid Android gets even stranger though. Count the beats in the section that starts just after the 2 minute mark, and you notice that some bars are in… 7/8! This is a rare time signature, probably best known from Pink Floyd’s 1973 Money or Dave Brubeck’s 1961 Unsquare Dance. It’s much more obviously spicy than unusual bar groupings; the odd number of beats breaks the regular “left/right” flow present in almost all popular songs.

Finally, if you listen to the confusing guitar melody that begins Let Down, you may discern that it’s actually in 5/4, another rare and erratic time signature, possibly best known from Dave Brubeck’s 1959 Take Five. The rest of Let Down is in standard 4/4, which the melody sits uncomfortably atop.