The lot of the rock wife is often not a happy one. Mostly, she is required to be dutiful, to fight off sexual competition by the legion and, where possible, keep her mouth shut.

The rock widow meanwhile, must follow the strict mourning protocol of the Jacobean court. For her remaining earthly days, she will be an ashen-faced cheerleader for the cause. If she jealously guards the back catalogue, fans will say she’s depriving them. If she shares the wealth and gives them all the recordings and lunch-boxes they demand, they’ll say she is exploiting the dead.

At 74, Yoko Ono knows all about the inequities of rock widowhood. Nearly four decades have passed since she became Mrs. John Lennon, yet only the bitter fallout from the McCartney-Mills union has finally allowed Ms. Ono to emerge from the unhappy spot reserved for Least Favourite Beatles’ Wife in the collective imagination. Until she witnessed her husband’s murder at close range – a tragedy that softened even the most unreasonable anti-Onoites – she was a scapegoat for many of the perceived evils in the world. Why did John Lennon leave childhood sweetheart Cynthia and young son Julian? Yoko Ono. Why did The Beatles split? That would be Yoko too. Why did our crops fail? Yoko Ono probably.

“When I wrote the song ‘Yes, I’m A Witch’ I was ready to scream,” she tells me. “I think it was important that I came up with that in 1974. I needed to shout it for the good of my mental health. Alright, alright, I’m a witch! Are you happy now? There, I feel better. But of course nobody was interested in anything I said or did at the time.”

Loathe as I am to contradict her, this is only partly true. Her late husband may have described her as “the world’s most famous unknown artist: everybody knows her name, but nobody knows what she does;” but Yoko Ono was not ignored. In fact, when she wasn’t being derided on racial grounds (an Esquire article during the ‘70s was nastily titled “John Rennon’s Excrusive Gloupie”) she was being mocked for her art. Famously, fans burned copies of Ono and Lennon’s Unfinished Music No. 1: Two Virgins album while record stores refused to stock it.

If she’s bitter it doesn’t show. Prone to repeating positive mantras and bouncy slogans (“We need to act on the wisdom life gives us” or “We need to all work together”) even when speaking the kind of undiluted hippie sentiment one might normally suffer badly, it’s hard not to feel the love. It’s the little things that win you over. She takes the trouble to learn your name and use it throughout the interview. She’s polite regardless of how stupid your questions are. She apologises profusely for having a cold. And she has such an endearing turn of phrase. There’s something of the valley girl about it. Her speech is peppered with California’s most notable contributions to the English language – “sorta’, “like” and “you know”. But there’s an unmistakably scouser rhythm in there, particularly the Liverpudlian talent for dry comic deflation.

“When I wrote ‘Death Of Samantha’,” she says. “It came from a dream or a vision or something. Now I hear it and wonder ‘Oh my God – what was going on there?’”

Her people – they who must be obeyed – have requested that I keep the questions to the new album and ask “nothing about John”. Fair enough, though barely four minutes have passed before she starts laughing at some small recollection.

“‘Cambridge 1969’ was really just intended as a performance piece,” she recalls, “But John got all ‘yeah, yeah, yeah’ and fired up about it and insisted on backing music. He said not to worry. He’d provide the band. It would be great. Of course, it turned out he was the band.”

Back then, detractors often dismissed Ono as an avant garde chancer. Brian Sewell, the archly conservative art critic, dismissed her installations in characteristically dogmatic terms – “She’s shaped nothing, she’s contributed nothing, she’s simply been a reflection of the times... I think she’s an amateur, a very rich woman who was married to someone who did have some talent and was the driving force behind the Beatles. If she had not been the widow of John Lennon, she would be totally forgotten by now.”

Though too daring for such bland palates, Yoko Ono has always provided inspiration for more enlightened individuals. Rather than the mad-as-a-balloon charlatan portrayed in the UK press, there’s an elegant simplicity to her most radical ideas. Recently, she decorated Liverpool with pictures of breasts and vaginas for that city’s fourth biennial. In Grapefruit, the book John Lennon kept under his pillow during the two years before they got together, her zen-like verse would ultimately inspire Lennon’s own unembellished manifesto. “Imagine a raindrop,” it read, “imagine the clouds dripping.”

A key figure in the post-Dada Fluxus art movement, Yoko Ono was collaborating with Ornette Coleman and playing Carnegie Hall while John still had Pete Best drumming behind him. Her marriage was not so much a leg up as the end of a promising career.

Shortly before his death, Lennon would hear The B-52s’ ‘Rock Lobster’ in a club and remark that Yoko’s music had finally caught on. The primal screams that defined ‘Don’t Worry Kyoko’ and her early performances would make their mark on such boundary-bulldozing talents as Meredith Monk and Diamanda Galas. Public Image Ltd. credit the Yoko Ono/Plastic Ono Band (1970), as the birthplace of punk.

“I’ve never seen a line between music and art and performance,” she explains. “And that’s a problem for some people. They don’t know what it is, so they don’t like it. But I wrote these songs and even I don’t know what they are.”

Untainted by the prejudices of their parents and grandparents, the post-post-Beatles generation have enabled Yoko’s music to bleed out from the experimental fringes. Suddenly, it’s acceptable to say what ears should have known – Yoko’s pop songs on ‘Two Virgins’ are much better than John’s. Suddenly, Yoko Ono’s records are outselling Paul Mc Cartney’s.

“I didn’t think it would be necessary to keep pushing the music,” she says. “But it turns out it was. I’m just glad I’m still around to see it.”

Now an elder stateswoman of no-wave, Yoko Ono is finally winning the acclaim she deserves. In 2001, YES YOKO ONO, a 40-year retrospective of her work, received the International Association of Art Critics USA Award for Best Museum Show Originating in New York City. In 2005 she received a lifetime achievement award from the Japan Society of New York. And since the turn of the century, cutting edge musicians have played witch-doctor with her back catalogue.

In 2002, the great remix project began in earnest. She dropped her first name for the occasion and scored a notable success with new versions of ‘Walking On Thin Ice’, remixed by dance artists including Pet Shop Boys, Orange Factory, Peter Rauhofer, and Danny Tenaglia. In April 2003, Ono’s ‘Walking On Thin Ice (Remixes)’ went to No. 1 on Billboard Magazine’s “Dance/Club Play Chart”. (Ironically, on the 12” mix of the original 1981 version of ‘Walking On Thin Ice’, Lennon can be heard commenting “I think we’ve just got your first No.1, Yoko.”)

“I hadn’t really given it a lot of thought before I heard it,” she recalls. “I was originally approached when I was deep in recording Blueprint For A Sunrise and when you’re doing studio work like that, you get really absorbed. Usually I would say no to that sort of request, but somehow I said okay. I wasn’t expecting anything. The next thing I knew it was done. I listened and I was totally choked up. I cried, you know.”

She was similarly overjoyed with Yes, I’m a Witch, the latest collection of remixes and covers by various artists including The Flaming Lips, Cat Power, Antony, DJ Spooky, Porcupine Tree and Peaches.

“Indie music is for now and for the future,” says Ono. “And of course I am too. Some artists just approached us when they found out I was allowing people at the back catalogue. We approached others. And it’s great that all these artists were involved, that transcend movements or genres. I like it that way.”

Obviously, she can’t tell us what her favourite retooling is but she sounds even giddier than usual talking about The Flaming Lips’ deconstruction/reconstruction of ‘Cambridge,1969’.

“When I heard The Flaming Lips were asking to record `Cambridge, 1969’, I wondered what they were thinking,” she laughs. “I mean, it’s one of the most far out things I’ve ever done. I was very proud of it at the time – surprise, surprise, well, not really a surprise – I’m still one of those very narcissistic people. But nobody else liked it.”

Listening to ‘Kiss Kiss Kiss’ dirtied up by the potty-mouthed Peaches, the brash sexuality still catches one unawares. I know Yoko recently posed in hotpants in a stand against ageism, but can she still feel as rampant as she did recording ‘Double Fantasy’?

“Oh yes,” she says. “I listen and think ‘oh, that’s hot’. It’s weird because that’s exactly what people didn’t like about it in the first place. When I used to perform, they turned my voice down for those bits. Now you hear the ‘ohs’ and ‘ahs’ turned up in the mix. Times have changed. And it’s great.”

Equally, one is struck by her go-get-’em politics. Events may have moved on since she recorded songs about Bloody Sunday, but decades later, tracks like ‘Sisters O Sisters’ from her feminist album Feeling The Space seem disconcertingly relevant.

“Feeling The Space was very much a feminist album,” she says. “It was literally a space I created for women – a woman’s album, I explained it all, about being a woman, not as an angry place but as a different place. And nobody wanted to know. We live in such a complicated age; we have to focus on uniting, we have to focus on peace. But it’s easy to forget about the woman’s condition. And the woman’s condition is very bad. People assume we have equality when, if anything, there’s a backlash going on against women.

“I don’t want to tell other women what to do, but in the time that’s left for me, there are certain issues I want other women to think about. One in every four admissions to the emergency unit is a domestic abuse victim. That’s not in the third world. That’s in the United States. That’s a real danger. It’s like if you’re going to be like that, then naughty, naughty girl, this is what you get.”

In ‘Death Of Samantha’, another feminist anthem rejigged for Yes, I’m A Witch, Yoko sings “Every day I thank God I’m such a cool chick”. Does she still feel that way I wonder.

“Oh yes”, she purrs. “Aren’t we all cool chicks?”