The Moody Blues have, for 40 years, been one of the most enduring and loved bands in the world.
More than 55 million album sales testify to their popularity and their catalogue contains some of the most ground-breaking songs in music history.
From their R 'n' B beginnings and their solitary UK chart topper Go Now, they transformed seemingly overnight into masters of symphonic rock.
This was no doubt due to the arrival of guitarist and singer Justin Hayward who, along with bassist John Lodge, steered the band away from the obscurity they had found themselves in and made The Moody Blues one of the biggest bands in the world.
It was in 1967 that the band released the album Days of Future Passed. It was one of the first "concept albums", telling the story – in music – of a single day.
The climax of the album, Nights In White Satin, became an all-time classic. For all that it never climbed above nine in the UK charts.
Other albums followed which included three Number Ones: On The Threshold Of A Dream, A Question Of Balance and Every Good Boy Deserves Favour. Two others, Seventh Sojourn and Long Distance Voyager topped the US charts.
With Justin and John out front, and writing the majority of the group's music, The Moody Blues pioneered the age of stadium rock, playing to massive arenas in the States.
"We have always had respect for each others' songs," John Lodge says. "When we played a rough version of any song we've written to the rest of the band, it immediately becomes a Moody Blues song and not a John or Justin song."
The band is currently touring the UK - visiting Manchester on Wednesday, September 24.
"It's been a pretty successful tour," he says. "We did about 50 concerts in the US and Canada."
So is the show they perform in the UK different to the one in America? "No, it's not! The wonderful thing about music is that it's all-encompassing. It's worldwide, and with us what happens in America happens in the UK and vice versa."
The band's longevity is legendary. John says: "Overall I think that it's because we've written our own songs from day one and we've never had to look outside the group for inspiration.
"It's not just the records either. Performing on stage has been a big thing for the Moodies and we've always been truthful about why we've done concerts, we always perform the songs as they are meant to be performed. Hopefully the audience will go away with something from the evening whether we've evoked an emotion or memory.
"We'll be doing a fair collection of songs covering most of the albums. We want to take the audience on a journey; there'll be highs and lows, up-tempo songs and slow ones. Of course there will be some songs that we have to put in."
Are there any new recordings planned? "We're looking at that right now," says John. "We've been in touring mode for the last three years and we've just released the CD of the 1970 concert at the Isle of Wight Festival. We'll be releasing the DVD of it just before Christmas. We're writing all the while so if there's time we'll get back in the studio."
What of the future?
"What we'd really like to do sometime is a concert with one of the orchestras. We tried to do one with the Halle but it never materialised and we also wanted to do a show with The Birmingham Symphony. That'd be great.
"One thing about being in The Moody Blues, is that you never know what's going to happen next!"
* The Moody Blues are at Manchester Apollo on Wednesday, September 24. Box Office: 0844 477 7677 or www.livenation.co.uk or 0844 576 5483