The past few years have seen a slew of side projects, with some of our favourite band members divorcing themselves from the day job in order to explore new musical avenues. Now, these new avenues can be rewarding, they can be awful, and some can be downright disturbing. But what motivates artists to head in a new direction? For your education and delectation, Joxley hereby presents his Patented Guide to the Seven Types of Side Projects.

The "I want to be more 'arty'"

You know how it is, you start off writing lo-fi indie rock with scream -along choruses and the world is your oyster. But, the years go by, you get a little stale, you begin lust after those hot bohemian girls, and suddenly the lad-rock doesn't cut it. You want to make your sound a little more sophisticated, but the bloke on drums is happy to sit swigging Stella and thinking of words that rhyme with "shag". So you take your leave, call up a mate from a less successful indie-outfit, and hook yourself up with an orchestra. Maybe even get a cartoon band, and voilà, you have a whole new sound, and those pretentious girls all want a piece of you. Don't believe me? Just look at Alex Turner - He wrote this, met her, then moved on to this.

The "I've done it once, I can do it again"

This one is a different breed entirely, one for musicians who built their bands up from scratch, and just want to do it again. I don't know why, maybe it's the thrill of the new, maybe they feel they have to prove something and the best way to do that is to beget another band. After all, you don't want people thinking the first was a fluke. Prime examples include serial band starters Jack White (White Stripes/Raconteurs/The Dead Weather) and Josh Homme (QUOTSA/EODM) and Nick Cave (Bad Seeds/Grinderman).

The "My band is going nowhere"

"We are on hiatus. We are not broken up. New album next year." That's the mantra of our next crop of moonlighters. They've been around for a while, and the ideas have naturally started to dry up, but they refuse to give in and call it day. So one by one they all disappear to make their own albums - first a guitarist who wants to sing, then a singer who wants to play guitar and eventually the drummer's diminishing returns, all the while paying lip service to the main band's longevity. To find these guys look no further than The Strokes - Albert Hammond jr has thrown out two albums, and Julian Casablancas one in the band's current dry spell. Of course, the website says the band will release a record in 2010. The Foo Fighters' Dave Grohl, and really the rest of the superstar band, is another prime example.

The "Look how cool my friends are"

Being a musician means you have cool musical friends. So what could be better than getting them all together and recording some tunes, perhaps even creating a (and you can only whisper this) "supergroup"? Whilst the Travelling Wilburys may have set the precedent, this has been embraced by younger collectives such as Broken Social Scene. Extra points are awarded if you convince one of your hot actress friends to sing with you* (step forward M. Ward).

*Unless of course she happens to be Scarlett Johansson

The "Who's band is it anyway?"

Ah, the good old meta-side-project. This is a much a rarer beast, but is still rewarding for the listener. You start off in someone else's part time band, bide your time, and then bang - branch of with your own solo project. It's a smooth move, and has worked well for The Raconteurs' Brendon Benson.

The "Don't call it a comeback"

Now this is hiatus trick gone pro. You've been around for ages and things have really started to stagnate, then some finally jumps ship and quits. Rather than hiring a replacement and doing the never-ending circuit of tours as band members slowly slip away, why not just call it a side project? Hell it worked for New Order as they seamlessly moved, minus Hooky, into Bad Lieutenant.

The "The famous one breaks free"

It's that seen from Almost Famous all over again, four blurry faces on the t-shirt, and one person out in front. But this isn't just cheap merchandise; this is your entire band's image. For some reason (usually prettiness) one person in the band gets more recognition than the rest. They don't have the heart to ditch the rest; indeed the music is still going good, so why bother? Instead just capitalise on your famous face with a side-project, and claim even more time in the limelight. It worked for Jenny Lewis a few years ago, and Karen O is following suit with her soundtrack for blockbusting "Where the Wild Things Are".

So my moggy friends, I hope that helps and informs you side-project spotting - but do let me know what I have missed. Those rarer varieties are always a pleasure to find, and if there are any more out there I'd love to hear of them.