You could spot them a mile away. Two mature ladies, one dressed in shocking pink from poncho to vibrant sweeping skirt, the other in psychedelic green - both heading purposefully along the Albert Dock to Tate Liverpool and the Summer of Love: Art of the Psychedelic Era exhibition.

But they weren't just there for the art. Sunday brunch at the Tate is part of Single in the City, a series of cultural singles nights at four venues around the city.

And it is just the latest in a wave of singles events sweeping the country's museums and galleries; from Bollywood nights in Birmingham to art2heart events at the Hayward Gallery and Victoria and Albert Museum in London.

But over orange juice and strawberries at Tate Liverpool, the atmosphere was a little strained. 'How do you meet someone when you're stone-cold sober?' muses 30-something Bob, smart in his suit. 'Oh, well,' he shrugs, 'If I meet someone, then I do. If I don't it's still a change from a normal Sunday routine.'

As the hospitality room fills, voices rise. 'I remember you from the salsa night at World Museum Liverpool,' one woman enthuses, 'and weren't you at the Best Dressed Man night at the Conservation Centre, too? Now, they were great nights out.'

The atmosphere is edgy at first, the women over-enthusiastic and the few men almost silent. But as the tour of the Summer of Love exhibition begins, the mood changes completely.

Donovan, Jagger, Oz magazine, Timothy Leary, Yellow Submarine, Janis Joplin's painted Porsche, the first Glastonbury, and suddenly the singles stop eyeing each other up and focus on the art instead.

'This is wonderful,' says Carole, 47, lying back amid the reds and blues of Verner Panton's installation Phantasy Landscape Visiona II. 'I was very nervous about coming along and needed to bring a friend with me. But I'll definitely come again.'

Mark, 28, agrees: 'I don't like bars, because everyone's eyeing everyone else up. But this is much more like a social event, and everyone's friendly.'

Hardly anyone, it seems, knows the gallery well: 'I've walked past it so many times, but didn't know all this was here,' says Mark adding: 'I'll bring the kids next time.'

Fifty-something Susan is equally enthusiastic: 'The salsa night was great, but I love this, too. The best thing is that it takes you somewhere different, somewhere you wouldn't usually go.' Others are also keen: 'I've wanted to come to the Tate for years,' one 50-something says, 'but somehow I never have.'

As part of an audience development project run by Team, an arts-marketing organisation on Merseyside, this is a step that Tate Liverpool has long wanted to take.

'Many had never been to the gallery before,' says Catherine O'Reilly, a press and marketing officer at Tate Liverpool, 'and so we reached an audience we wouldn't usually be able to reach. And people were swapping email addresses, and really talking to each other.'

Stephen Guy, a spokesman for National Museums Liverpool, agrees: 'This is a part of our policy of getting everyone - singles, married, whatever - to come to the museums and galleries, including those who don't generally visit.'

They reflect the city's regeneration too, he says: 'These events fill a gap in the market, and people definitely come back and bring like-minded friends.' But do glasses of red wine and art really mix? 'Drinks are kept in separate areas, and certainly there would be no red wine near art,' says Guy sternly.

The New Art Gallery Walsall claims to have hosted the first singles night in a museum at the beginning of 2001. When staff were looking for ideas for a Valentine's night event, it seemed the obvious choice.

'We had a lot of fun working on the Valentine's theme and decorating the gallery for one special night,' says Oliver Buckley, who organised the Walsall event. 'It was also a great way of attracting mass media attention.'

And while the organisers might have expected criticism from the purists, there was very little, says Peter Jenkinson, the then director of the gallery: 'To be honest, museums and galleries have always been places to go on the pull - late openings and organised events such as singles nights just formalise it.'

He says he doesn't remember much criticism: 'The events got good coverage in the local press, and the first one was live on the regional BBC TV's early-evening slot. And what sort of negative person is going to attack people getting together in beautiful buildings surrounded by stimulating things?'

Buckley says it became an effective audience development tool: 'It revealed a large potential audience of young professional people who would visit a themed evening opening, even if they would never consider coming in daylight hours.'

And from the public the interest was overwhelming: about 300 singletons attended the event, a high proportion of whom were first-time visitors.

'We used it to promote our collections and archives, for instance by reading some of the sculptor Jacob Epstein's love letters to Kathleen Garman, the collector and donor of Walsall's artworks,' remembers Buckley.

The singles nights petered out at Walsall and as organisers were encouraged to charge more, they found that people's expectations rose and they wanted more in the way of introductions. 'The nearest we got to offering this were salsa dancing classes, and a blues bar in the conference room,' Buckley says.

But lonely hearts in the Midlands needn't despair. Buckley, is now based at the Birmingham Museum and Art Gallery where there are regular singles nights linked to exhibition themes - an Indian-themed night to complement the Bollywood exhibition, and a 60s night to go with Art and the 60s on tour from the Tate.

Carmel Girling, the marketing and PR manager at the Birmingham Museum and Art Gallery, says that as a way of drawing new visitors to the museum, they're hard to beat. 'We've run several nights, and they're always a sell-out,' she says. 'People definitely come back, and it changes people's perception of what the gallery is about.

'Galleries should be enjoyable spaces, and we hope people feel more confident about coming back the following day,' Girling continues. 'People want to interact differently these days, and these events act as ice breakers. It's also part of audience development, at little or no cost.'

But can the events generate serious revenue for the galleries? 'Early on they made money, but now we're quite happy to break even since we're putting more effort into the staging,' says Girling. 'People suggested that we have a jukebox at the 60s night, for instance, and so we're learning as we go along.'

But for lonely hearts around the country, do singles nights work as a way of meeting interesting members of the opposite sex? Over brunch at Tate Liverpool, people are wary: 'Well, we do go on to a club somewhere usually, and who can say what's going to happen over a few drinks?' says Susan. 'But the art is the best bit.'

Carole agrees: 'Instead of pressure to meet men all the time, there's another focus, the art - and an amazing focus it is too. Put me down for the next one.'

Carol Davis is a freelance journalist