But almost immediately they were back in the studio and touring again. Only more than a decade later did singer/guitarist Hayward enjoy some personal fulfilment.
"We didn't have many great singles [in the 60s and 70s] and it wasn't until the 80s that we had big singles, Wildest Dreams and I Know You're Out There Somewhere. To have a record in the charts was wonderful for us.
"I was in my early 40s and to be recognised in the street as 'the guy in the video' and to have everybody love the record and hear it everywhere, was a great experience. I'd missed it the first time around because I was too busy or too ambitious - and probably too stoned. But the second time around, I savoured every moment."
The Moody Blues were one of the most musically innovative and productive bands of their period and their albums between Days of Future Passed in 1967 to Seventh Sojourn in 1972 anticipated the prog-rock that followed, but they managed to deliver albums of self-contained songs without the bloating that marked much prog.
Many of these early records - on which they played an astonishing array of instruments from flute to sitar and Mike Pinder played the mellotron, an instrument he apparently introduced to Paul McCartney and John Lennon - were, loosely, concept albums but not so much that they were constrained by any narrative. They were symphonic psychedelic pop albums from which sprang singles.
The Moodys also enjoyed a rare association with a single producer, much as the Beatles had done with George Martin. The Moody Blues had Decca's in-house Tony Clarke (often credited as the sixth Moody, with his photo on the cover) and in 1969 - a year after the Beatles launched their Apple label - they started Threshold Records to keep creative control of their work, before bands like the Rolling Stones and Led Zeppelin did the same.
In many ways they were in the vanguard of the modern musical landscape but Hayward - who also pursued a successful solo career and sang in Jeff Wayne's War of the Worlds - admits they were lucky.
"We had a great record company with wonderful recording studios and all they wanted us to do, after they had success with Days of Future Passed, was let us just keep on making records. Then we went to America, taken by [promoter] Bill Graham and arrived at the beginning of FM radio taking off, and our stuff was perfect for it."
Hayward also says producer Clarke "could sit back and see the whole album as a movie in front of him, and he talked in that esoteric way about what we should be feeling and what should come through".
"We were very lucky to have people around us who concentrated on the music and not us as celebrities, but we chose that in the early days, too. There was a feeling in the band in the first few years that we were doing something arty. There wasn't a snobbery about it, but we just wanted to play music and immerse ourselves in it. It's only later you start to come out of that shell when publicists demand you go on morning television and you have to play your part and promote the stuff.
"In the early days we didn't, we just did the occasional television show, which is why, sadly, there is a lack of early film of the Moody Blues."
Hayward - who was 19 when he wrote their classic Nights in White Satin - says the three remaining Moodys who crafted those seminal albums (himself, bassist/singer John Lodge and drummer Graeme Edge) "are offered so much work now we could be on the road 365 days a year. We seem to be a bread-and-butter band for a lot of promoters."
Today technology allows them to replicate their studio-crafted music in way never possible in the 70s when their use of the mellotron set a benchmark on record but couldn't be reproduced on stage. Their touring band includes singer Nora Mullen on flute, harmonica and guitar who was formerly of the LA Symphony "who grew up on our music" and Hayward says they play songs from all of their classic albums. And, just as they were four decades ago, they are still making music and still touring.
"We seem to be on the road maybe six or seven months a year, which is a lot. But I enjoy it and to be in a band that does my stuff great is all I ever wanted."
LOWDOWN
Who: Symphonic rock pioneers the Moody Blues
Where: Michael Fowler Centre, Wellington, Nov 26; Civic Theatre, Auckland, Nov 27
Significant albums: Days of Future Passed, with the London Festival Orchestra (1967); In Search of the Lost Chord (1968); On the Threshold of a Dream (1969); A Question of Balance (1970); Sur la Mer (1988)
- TimeOut