MACKENZIE was 13 when she ran away from the safety of her mum's home and turned up on her dad's doorstep. It was the early Seventies so she wasn't entirely surprised when he opened the door wearing a floor-length, tie-dyed caftan and smoking a joint. But she was surprised when he began laying down the law.

You must come home at least once a week, she was told, and, if you stay over with a guy, always take a change of clothes "because a lady is never seen in daylight hours wearing evening clothes". Talk about Victorian values, man.

After learning to roll joints for her dad, Mackenzie soon learned to smoke them too. Then she progressed to acid, going to school on a constant high every day for three months, and finally intravenous coke, which her dad helpfully injected for her the first time so she didn't mess up.

In the five years since she first arrived on her dad's doorstep, she was also evicted from the house when her dear old Pa went to New York for the weekend and forgot to come back and she had sex with several of his pals.

A clear cut case of parental neglect? Nah, this was the Seventies man, peace and love were all around. And anyway, Mackenzie's dad was a famous musician, you know, so don't get all heavy and freaked because it's a scientific fact, you know, like something proved by a real bread-head corporation, that creative guys just don't do responsibility.

Sorry, but I just don't buy it. Being a famous musician is not an excuse for child abuse. Just because Mackenzie's dad was the late John Phillips of the Mamas And The Papas and because most of the men she slept with were his contemporaries - including Mick Jagger, who apparently said he had been waiting to have sex with her since she was ten but had the good grace to wait until she was 18 - doesn't make her childhood acceptable.

Unfortunately, however, it also doesn't make her childhood unique. The 70s were littered with lost children, left to fend for themselves by parents seeking the adoration of millions while ignoring the love waiting for them at home.

The November issue of American magazine Vanity Fair carries fascinating interviews with the likes of Mackenzie Phillips, China Kantner (daughter of Jefferson Airplane's Grace Slick and an alcoholic at the age of 12), Francesca Gregorini (stepdaughter of Ringo Starr who describes her childhood as "opulence, beauty, sickness and despair"), Moon Unit Zappa (daughter of Frank, who should have been locked up just for burdening her with that name) and Ione Skye (daughter of Donovan, who denied she was his child for many years) as well as various offspring from the Stewart and Jagger clans.

All their stories are different - some were neglected while others were actively abused - but all were undeniably damaged by their parents' success.

But things have changed. And for once it seems they have actually changed for the better.

Consider modern mums and dads in the music biz such as Melanie Brown, Damon Albarn, Gabrielle, Melanie Blatt, Madonna, Natalie Appleton, Norman Cook and the numerous other big-hitters who have happily swapped sex, drugs and rock 'n' roll for love, an epidural and bums 'n' bibs. Heck, even Liam Gallagher has turned from being a bit of a bad lad into not such a bad dad after a few hiccups in the early stages (well, you can't remember the name of every woman you impregnate, can you?).

And look at the Queen Mum of modern pop herself. Posh Spice - or Skeletor, as I like to call her - has many faults but she is undeniably a very loving and attentive mother. She and her incredibly talented husband, who unfortunately appears to have an IQ only marginally bigger than his boot size, are indulgently saccharine, publicity-addicted media junkies who would wear matching bin liners if they had Gucci labels. But you do get the feeling that they would pack their bags and move to the Outer Hebrides tomorrow if they felt Brooklyn was at risk in any way.

OK, so their bags would be Louis Vuitton, they would insist that the Hebrides be carpeted in shagpile from coast to coast and moved somewhere warmer, Antigua perhaps, and the locals would have to officially recognise them as their King and Queen, but the fact remains that they would do it in a heartbeat.

Posh and her fellow modern muso mums and dads who spend time with their kids now, for the deceptively short period when they are young enough not to be terminally embarrassed by their parents' public personas, will be able to look back in 15 or 20 years time with real joy and pride in a job well done.

How different things must be for our rock idols from the 70s. For many their children's formative years must be little more than a gaping hole in their consciousness.

They may have vague recollections of young girls looking adoringly at them - but were they their daughters or their conquests?