When you're a musician, it's a particularly hard decision. How can you be sure your best work is behind you? How do you know if you've got one good album left in you or not?

One artist who has apparently pulled the pin lately is ex-Genesis drummer, Grammy-winning solo artist and Disney movie soundtrack specialist Phil Collins.

Collins has thrown around the phrase ``retirement'' a fair bit in recent years - he even did a Final Farewell tour in 2003.

The semi-official announcement that he was hanging up his drumsticks and renditions of In The Air Tonight was greeted by a sigh of relief from many music fans.

But, as stated before, it's hard for a musician to know when to stop.

To help make this decision easier, the brains trust at Musicology has come up with a list of musicians who should retire.

The Rolling Stones

LET'S get the obvious one out of the way first. The main reason The Stones should be put out to pasture is that they're actually still good and it's always better to get off the stage leaving fans wanting more. As a live unit, they remain one of the best bands on the planet and their last album A Bigger Bang wasn't half bad. This is why they should count their chips and cash it in. That they've lasted this long is a miracle (although Keith Richards will probably outlive us all) but to continue on is just pushing your luck. It would be better to go out on their own terms rather than have their legacy forever tarnished by one of the members (most likely Charlie Watts) dropping dead mid-Gimme Shelter.

Cliff Richard/Tom Jones/Rod Stewart

THIS trio of former heart-throbs (who are now probably on medication to ensure their hearts don't throb too much) still make good money touring the cabarets and dinner-and-show venues of the world. Their best work is long behind them, however, and their voices, particularly Jones', are starting to crap out. As for those women throwing their underwear at them, they're old enough to know better - in fact, their grandkids are old enough to know better. If these artists stopped, everyone would bow out with their dignity intact, possibly even the grannies hurling knickers the size of a one-man tent on stage. John Farnham would be in this category too if he hadn't already retired for the 12th time.

Sting

N OW that The Police reunion is over, Sting has nothing left to offer. Hardly anyone liked his past few albums (although Brand New Day had its moments) and he hasn't had a really killer single since 1988's Englishman In New York. Remember when he did that god-awful track with Rod Stewart and Bryan Adams? People have been executed for less. He should have handed in his resignation right there and then. Maybe we can scrub over that bit of Sting's oeuvre if he agrees to retire now.

Chris Cornell

THE former Soundgarden and Audioslave frontman is on his last legs and really should just pack it in. He's past it - even his Audioslave bandmates realised this and went back to Rage Against The Machine. Cornell's working on a new album with so-hot-right-now producer Timbaland, and if it's a winner, a retraction will be printed on this page. If it sucks as much as his last solo album and recent Bond theme, then there will be no need for corrections. If his next solo album fails, then an instant Cornell retirement will save us from a Soundgarden reunion that will only tarnish their legacy. And while we're talking about former grunge-era frontmen tarnishing their legacies... Billy Corgan, you're next.