The Metro featured an interesting quote from Tori Amos this morning - "The music industry is a vicious business. It chews women up and spits them out."

Some of the biggest stars in the music industry right now are women - it's easy to come up with a few just off the top of your head. Rihanna, Lady Gaga, Katy Perry, Lana Del Rey, Adele, Taylor Swift... even Florence Welch. So on that note, it'd be easy to say that Amos is wrong. Clearly, she is - just look at all these women.

But Amos isn't saying that it's impossible for women to get success - rather, the point is the nature of the success. It's difficult thing to talk about, because it's a multi-faceted problem.

One of the main points is the sexualisation of women - a tired point, admittedly, but not unimportant. Think Katy Perry and think of cupcake bras, think Rihanna and think of Instagram bikini photos and THAT S&M video. Aside from those obvious points, there's a myriad of subtler issues surrounding this. Maria Diamandis, for example, who had her video for 'How to Be a Heartbreaker' pushed back in September because she looked 'ugly'.

"So, someone at my record label wont let me release the video bc I look ugly in it apparently," Diamandis wrote on Twitter. "We need more $/ time to paint out ugly parts

"They still hope to have the video out by the end of the week and if not, I am happy to leak the 'minger' version for my fans."

This isn't an isolated example - and it makes you wonder how many other female artists simply don't speak out. In 2008, Amanda Palmer hosted a 'Re-belly-on' after her label asked her to cut shots from the video 'Leeds United' because they thought she looked fat. Palmer is, for the record, the furthest thing from fat. When was the last time you heard of a male musician not looking good enough in a video?

And yes, it's easy to point at boybands like One Direction who are marketed on their good looks - but it's not a fair comparison to make. If they talk about sleeping with their fans, there's a 'boys will be boys' attitude - when Britney Spears was marketed as a sexy schoolgirl, she also had a chaste and pure image to maintain. Taylor Swift is being hailed in America for being 'wholesome'. Girls are allowed to be sexy, but not too sexy. Pure, but not a prude.

Look at Susan Boyle, who is unreservedly treated as a joke because of her appearance. Again, you can point out that anyone that eccentric on Britain's Got Talent is going to be laughed at, but that doesn't explain why comedians are still using Susan Boyle as the punchline of any joke - as easy shorthand for someone ugly that no one would want to sleep with.

And if a female singer isn't completely ugly, then labels and the media take that and run with it. Lana Del Rey was the ONLY GQ coverstar to be naked on the Men of the Year 2012 issue, with all four men being fully clothed.

If the focus for a female singer does happen to be on their music - God forbid! - then it's only in comparison to other female singers - not to men who create music in the same genre. In an NY Times blog, Lana was described as "the perfect antidote to Rihanna-Gaga overload - dare we say, a skinnier Adele, a more stable Amy Winehouse," despite having very little in common with most of them musically.

And Star Tribune decided to use this description of Florence, "Florence may use the same stylist as Lady Gaga, the same producer as Adele and the same co-writer as Duffy. Flo may have a sense of drama like Gaga but not the sense of spectacle. Flo may have an indelible voice like Adele but no warmth and humanity. Flo may have the same natural beauty as Duffy but none of the relatability."

Literally the only comparison they could think to make was 'she's beautiful and so is Duffy' - and they then thought that was worth writing down.

And a Salon article about Taylor Swift had this to say: "The indulgence of last decade produced enough pop trash to fill a trailer park in East Peoria: Britney Spears, Christina Aguilera, Ashley Simpson, Jessica Simpson, Mandy Moore, Kelly Osbourne, Avril Lavigne, Hilary Duff and even back benchers t.A.T.u, M2M, Hoku, Skye Sweetnam, Brooke Allison, Willa Ford and many others."

Every single example of pop 'trash' that they could think just so coincidentally happened to be women (and, interesting to note, they couldn't even take the time to get the correct spelling of Ashlee Simpson's name).

Longevity as any artist is difficult, and especially as a woman - Madonna, for example, is repeatedly mentioned in the press as someone who should 'cover up' (so can we tell Iggy Pop to put a shirt on?). But thinking that female artists don't have many more problems in an even shorter career is just as problematic. Chewed up and spit out? Tori may well have a point.

Below, when music stars pose nude for magazine covers (and how many of them are women)...