Numbers of the Beast #2: A skew loose?
Posted in Indulgence, Uncategorized, music stats on June 24th, 2010 by Alex
Lemmy - a skew loose?
So we’ve learned that some bands have pretty obsessive fans. It’s nice that they’re listening to a lot of Opeth’s music, but are they just getting gooey over one album or even a single track? Let me demonstrate what I mean at its most extreme – the one hit wonder. This is not a phenomenon that’s particularly prevalent in the metal genre, so we’ll look to the genre most susceptible: pop. When I think of one hit wonders, one track always seems to spring to mind: Deep Blue Something – Breakfast at Tiffany’s. It’s a nauseating ditty that seems to blight the airwaves still, even 17 years after its release. Let’s see what Deep Blue Something’s last.fm listener profile looks like shall we?
Breakfast at Tiffany's and some other tracks
Oh dear, a staggering 83% of Deep Blue Something’s overall listens were from that one track that you doubtlessly find occasionally looping round in your brain, eating away at your soul. In statistical speak this effect is broadly referred to as Skew or Skewness. According to Wikipedia “In probability theory and statistics, skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable.” Ummm, yes. Put more simply, and in the current context, if folks are listening to 1 or 2 songs from a bands catalogue lots, and hardly anything else, then that band’s playcount would be considered to be skewed. In last.fm circles, the calculation for this is often referred to as AEP (I won’t bore you with what it means, other than it’s a fairly arbitrary statistical calculation) which gives an indication of skew across a band’s top 50 tracks. The AEP is a value of between 0 and 5 that indicate skewness, where 5 is not skewed at all (all tracks listened to exactly that same amount of times) and 0 (or less) is very skewed. Thanks to that wretched track, Deep Blue Something’s AEP is -13 (yes minus 13), compared to, to pick another more successful pop act, Michael Jackson, whose AEP is a respectable 2.7.
So, how does my list of metal acts fare in the AEP stakes? Let’s have a look:
| Artist | AEP |
|---|---|
| Devin Townsend | 4.43 |
| Neurosis | 4.41 |
| Blind Guardian | 4.37 |
| Napalm Death | 4.35 |
| Opeth | 4.32 |
| System of a Down | 4.3 |
| Cathedral | 4.29 |
| In Flames | 4.28 |
| Tool | 4.27 |
| Children of Bodom | 4.25 |
So here we see a different picture again. These are very high AEP’s, which indicates that the bands’ top 50 most listened to tracks are listened to a comparable amount of times. What this suggests about a band is that they’re not just a 1 trick pony – their fans love a wide variety of their tracks rather than listening to just a couple before moving on. Predictably, In Flames make a reappearance, Opeth remain strong, and we all knew that Devin Townsend fans were an obsessive bunch (this incidentally, doesn’t include all the numerous variations on Townsend’s solo band names, or SYL, who are #32 in this list). This is a respectable list – Neurosis, Tool, Cathedral, all at the top of their game and widely respected, and there’s a real mix of genres here. Perhaps this is a demonstration of a quality all round band, no filler. Albums bands, career artists.
This may all be true, but things get a lot more interesting, and confusing, if we consider the other end of my (far from exhaustive) list:
| Artist | AEP |
|---|---|
| Nirvana | 3.03 |
| Ozzy Osbourne | 2.53 |
| Black Sabbath | 1.84 |
| Soundgarden | 1.69 |
| Mötorhead | -1.28 |
Yeah, a bunch of flash in the pan, one hit wonders – non-players. Oh wait…those would actually be some of the most revered and respected bands in the rock/metal arena! What went wrong? I’ll give you 5 reasons: Smells Like Teen Spirit, Crazy Train, Paranoid, Black Hole Sun and last, but by no means least, Ace of Spades. If you don’t know exactly what those 5 labels refer to, then you must have been living in a cave for the past 40 years. Now, for many of these bands, these tracks are the worst, but not the only, offender (Come as You Are is a close second for Nirvana for example), but each bands have significant skew thanks to these BIG hits in their back catalogue, something that few of our least skewed acts have. So we’re still missing a dimension here…
Let’s take Mötorhead, who are skewed into minus numbers by their ‘classic’ (quoted as Lemmy doesn’t reckon it’s their best track) Ace of Spades. Now, as we saw earlier, Breakfast at Tiffiny’s accounts for 83% of DBS’s overall listens, so what of Ace of Spades? Well, it clocks in at a modest 10% of Mötorhead overall listens. So where are all the other listens going? Well, remember that AEP is calculated across a band’s top 50 tracks, so the majority of listens of Mötorhead’s tracks must be happening outside of their top 50. Given Mötorhead’s rich and voluminous back catalogue this is hardly surprising.
So, there’s another calculation that will tell us which bands benefit from this sort of listener attention, it’s called the Long Tail and we’ll discuss this in the next article.
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. Although not necessarily representative of the dense melancholy pseudo-prog on this involving album, it’s an enjoyable atmospheric rock song. This spooky Blair Witch meets Area 51 video, however, casts a completely different aura over this innocuous number. A collage of largely static, monochrome images tell of monoliths and aliens with newspaper cuttings and amorphous landscapes all spliced together in time with the music. Quivering and edgy, this is actually a little unsettling.
is nothing like anything he’s ever done before. Part of a 4 album cycle, all due this year, Ki is the mellow one. The albums will get heavy (
. Nice one Dev!
