It is 40 years since a 19-year-old Mike Oldfield released Tubular Bells, an instrumental concept album that has become one of the more unlikely global hits.
The British teenager's ambitious project, involving him playing more than 20 instruments, was deemed unmarketable by many music industry insiders, yet a young Richard Branson chose the work as his Virgin label's debut release in 1973.
The rest is history: Tubular Bells, which has now sold more than 25 million copies, was an early cornerstone of Branson's empire.
The album has also provided opportunity for others. Australian multi-instrumentalists Daniel Holdsworth and Aidan Roberts have created a ''frantic'' tribute, Tubular Bells for Two, which they will perform as part of the Festival of Colour in Queenstown and Wanaka this week.
Oldfield might have taken six months and many overdubs to record his work, but Holdsworth and Roberts attempt to do the same in a matter of hours.
The challenge includes juggling pianos, organs, electric and acoustic guitars, bass, mandolin, tuned percussion, drums, glockenspiel, loop pedals, synthesizers and, of course, tubular bells.
''The whole thing came together by accident really,'' Holdsworth explains via phone from his home near Sydney.
''Both Aidan and I are huge record fans and we got together one night to listen to music. We had the record on and thought we'd play through it.
''We just thought we'd have two guitars and play it from start to finish. Then we thought, `oh, we should put some piano there'. Before we knew it, we had a lounge full of instruments. At some point, we thought maybe we should perform it.
''We live in the Blue Mountains just out of Sydney and there was little cabaret room out there, so we asked if we could use it for a quiet night.
We thought we might play to 20 friends and family; the next thing we know, it's sold out and we're performing to 150 people.''
An idea that formed over a couple of wines in 2008 and was intended to be ''just a bit of fun'' has blossomed into a project that has taken the pair to festivals around Australia , the Pacific and beyond.
The show, which won a Sydney Fringe Award (2010) for Best Musical Moment, made its European debut at the Edinburgh Fringe Festival in 2012. This year the pair will perform more than 100 shows.
''All sorts of people come and see the show,'' Holdsworth says.
''It's not just Mike Oldfield fans. We get a lot of younger people coming up to us afterwards and saying, `you know what - that's the first piece of music in which I've really been absorbed in a long time'.
''I think the record tells a whole story. It takes you on a journey. It has a beautiful arc. It's quite a cinematic experience, with highs and lows, a lot of emotion.''
There's plenty of emotion on stage, too, Holdsworth says.
''The first show we did, we got about 15 minutes into it and people started laughing. We suddenly realised that, in trying to run around and play all these different instruments, there is this tension.
''There was one moment when Aidan was playing the piano and had to also try to pick up his guitar, but he couldn't quite reach it; I was busy on the other side of stage so I couldn't help him.
''For us, it's a case of struggling with instruments, falling over ourselves. We never know what's going to go wrong. I think what is important from a theatrical aspect is that it has to be almost impossible to perform. That keeps a level of tension.
''Everything is performed live on stage. We had one guy review us last year who said we played to backing tracks. I don't know what show he was at.
''We still go back and listen for other parts to add. It's definitely always a challenge. But that ambition to get it perfect is what drives us every night.''
Both Holdsworth and Roberts continue to play in other bands and musical projects, but have found their own take on Oldfield's concept has encroached on their various activities.
A few years ago Holdsworth was a teacher, while Roberts was working for a bank. They are now full-time musicians.
''It's kind of weird. We've been asked to do all these shows this year to celebrate the 40th anniversary of the album, but Mike Oldfield is still alive, though he's not really performing much,'' Holdsworth says.
''Over the past few years we've met a lot of hardcore Mike Oldfield fans from right around the world.
''Every now and then you come across someone ... there was this guy in Scotland who came up to us and asked us to sign an original copy of Tubular Bells. I just wrote in big letters across the front, 'I'm not Mike'.''
See them
Tubular Bells for Two will be performed at the Queenstown Memorial Hall on Thursday, April 18; and Central Lakes Trust Crystal Palace, Wanaka, on Friday, April 19.
Tickets are available from www.festivalofcolour.co.nz or (03) 443-4162.
