What with one thing and another, Massive Attack have taken their time. Their three albums to date have taken as long to appear as The Beatles' entire recording career. But, gradually and quietly, the trio has insinuated itself not only into the record collections of the music-loving public, but also into its psyche, if recent polls are anything to go by: their albums Blue Lines (1991) and Protection (1994) have a habit of popping up in those top-albums-of-all-time charts.
Their slow-motion, cinematic sound came about by an unorthodox route - evolving from the 1980s and their years as DJs and MCs with their sound system, the Wild Bunch. They are not musicians in the traditional sense: their music has emerged from the magpie school of sampling and electronic whizzkiddery, and has gone on to engender a new musical genre, dubbed "trip hop" by the media. Other similarly downtempo Bristol groups have followed in their footsteps, including their former collaborator Tricky, Portishead, Roni Size and the Reprazent collective and Alpha, who are signed to Massive Attack's label, Melankolic.
Massive Attack's slow-burning torch songs, spacey raps and mellow grooves are soulful, seductive, anthemic even, and their first two albums encapsulated, but also outshone, the dance music of the early 1990s. In 1994, the band won a Brit Award for best dance act, even though - as they pointed out at the time - none of them knows how to dance. The distinguishing feature of their variety of dance music is that you don't dance to it. Unless it's a very slow dance.
Former Wild Bunch member Nellee (Paul) Hooper, who produced Protection, is now one of the world's most sought-after producers, having worked with Madonna, Bjork and, more recently, All Saints. It was Nellee who, a couple of years back, helped mastermind a collaboration between Massive Attack and Madonna - a cover of I Want You for the Marvin Gaye tribute album. The band have also contributed music to a number of film soundtracks - including Batman Returns and Jackal - and their string-soaked elegy to lost love, Unfinished Sympathy, has been covered by Tina Turner. Increasingly, their sound has become a blueprint for the music being made by dance, rock and pop acts alike. They are among the most influential groups in contemporary music.
Now they have just completed a remarkable third album, Mezzanine. The record has been much anticipated (it's been four years since the last one, after all). They admit themselves that they are easily distracted, and Bristolians are renowned for their slacker, slow-paced approach to life. Then there was the endless negotiating. "It's not a harmonious thing with us," explains Grant. "It works more in an individual way, with all the pieces making a whole. We've begun to realise that we're all completely different."
The three of them have in common the distinctive Bristol burr, and the Bristolisms (they all call each other "Jack"), but they are, outwardly at least, quite unalike. Mushroom has boy-like features and flawless, caramel-coloured skin (his father is South American, his mother white and English) and favours a New York homeboy mode of dress. He's softly-spoken, with an expression that hovers between amused and bemused.
Grant Marshall, at 38 the eldest of the three, is an imposing-looking figure: lean, black and very tall. His manner is warm, easygoing, composed; he's an elegant dresser - minimalist, retro (with a touch of Prada).
Delge is an Italian-English fast-talker - usually clothed in (designer) combat trousers and T-shirt, twinkly-eyed, deliberately ill-shaven, with angular features and a Sid James laugh. They're all charmers.
The three of them have been together, in one way or another, for 15 years. Together, they have made the transition from their 20s to their 30s; from obscurity to renown; from a cosy, modest, provincial existence to the glossy, pop jet-set; from a gang of mates to a corporate, profit-making enterprise. A few tiffs are only to be expected.
"Any big row in Massive Attack is never about one incident," explains Delge. "It's always a culmination of all the years we've been together. It's about all the incidents rolled into one." All three gravitated towards Bristol's comfortably multi-racial, anglicised hip-hop scene, each fuelled by his own obsessions. "Having the right gear, having the right music," was the thing, says Delge.
It was Grant Marshall and Nellee Hooper who, in 1983, first formed the Wild Bunch crew, named after Sam Peckinpah's epic Western. Soon, Miles Johnson joined them, along with Claude Williams and graffiti artist Delge Although they were picking and mixing from others' records, the sound they created - switching between two turntables, and rapping over the music into microphones - was identifiably their own.
But what made their name was the Wild Bunch's unerring ear for music. They played at warehouse dos in London as well as in Bristol, impromptu outdoor gatherings on the downs in the summer, and house parties.
It wasn't all one big party, though. There were rivalries, jealousies, bitchiness. "It's always been like that," says Delge. He was sacked from the band on their first trip to Japan, but within a couple of months he had been rehired.
In 1987 Miles and Nellee left for London and the Wild Bunch released a single, The Look Of Love. But, again, a row flared up and the crew split again, this time in earnest. Nellee was soon working with north-London sound system Soul II Soul on their new recording venture, while Miles vanished to Japan. It was a dramatic exit, amid a tumultuous clash of egos, and he hasn't been back since.
Grant, Delge and Mushroom, meanwhile, formed the creative core of Massive Attack, and released a single independently, Any Love, featuring the falsetto vocals of Carlton. Neneh Cherry's husband, Cameron McVeigh, became the band's manager, and they were signed up by Ray Cooper and Ashley Newton to Circa records in 1990.
The following year, the album Blue Lines was released, with guest vocals by Shara Nelson, formerly of the On U Sound system. The album also featured the voices of Tricky and Horace Andy. It was a resounding critical and popular success. Things were looking good.
But then Shara decided to leave and pursue a solo career.
They spent months searching in vain for a new singer, and then embarked on a small-scale tour of the east coast of the US. Without the know-how to perform as a live band, they resorted instead to the sound-system format of two turntables and a microphone. The whole thing was misconceived, badly marketed and a flop.
"We didn't know what to do next," says Delge. Then, galvanised partly by former associate Nellee, who offered to produce their next album, they gathered vocalists Nicolette and Tracey Thorne (of Everything But The Girl), along with Tricky and Horace Andy, and emerged with Protection, which sold 1.1 million copies and consolidated their status as a major force in British pop. That was 1994.
They set to work on their live show - appearing at festivals in the past couple of years, notably Phoenix - and wrote film soundtracks: for Batman Returns, Welcome To Sarajevo and the Robert De Niro/Wesley Snipes film, The Fan. Then there was the Madonna track, "a short, sharp shock", according to Delge. "She sang it like a bird practically the first time round."
Mezzanine, the new album, was co-produced by the band and Bristolian Neil Davidge, and is more visceral than its smoother predecessor. A few years back, the band had approached Liz Fraser - formerly of the Cocteau Twins and This Mortal Coil - to work with them, but she had turned them down. This time, however, she was keen to collaborate. Her voice has proved an excellent foil for Massive Attack - particularly on the poignant single, Teardrop.
The live feel of the album is the most noticeable change in direction. Massive Attack seem to be following a kind of reverse career path: whereas, traditionally, bands start out playing live, then hone and refine their music in the studio, Massive Attack were sampling in the studio years before they ever even attempted a live gig. Only now, 11 years after they formed, have they finally knocked their live show into shape and, as a result, real instruments have come to the fore.
Working closely with people who became your friends when you were a teenager must be very strange - it must be difficult to look at one another afresh, to allow each other to change and mature - so it's unsurprising that they can be quite hard on each other. But, somehow, it all works. There must be some kind of inner equilibrium. And they know that, which is why they are not about to split up, whatever the rumours. "Not now," says Delge. "We've got a new album, and we're on a world tour. Splitting up would be a pretty bizarre thing to do."
Massive Attack's new album, Mezzanine, is due out on Monday.