But, in 1974, the Moody Blues announced their dissolution, after releasing a swan-song greatest hits collection, the double-album "This Is the Moody Blues."
"I don't know if it had anything to do with the creative part; it had more to do with the fact that our lives had changed so much," Hayward recalled. "I was 19 when I joined the Moody Blues, and I had known no other life; I had gone from being a broke teen-ager with no money to superstardom and had developed no real life outside of the band.
"At the time, we were getting more and more enclosed and introverted, and there was just nothing left to talk about; we needed to go out and do something different."
So they did. Hayward and bassist John Lodge cut an album together, 1975's "Blue Jays," followed by a pair of solo albums. The three other group members--flutist Ray Thomas, keyboard player Pinder and drummer Graeme Edge--also issued a solo album or two apiece.
But, by 1977, the Moody Blues were a group once more, reuniting in the studio for 1978's "Octave."
"We were apart for three years, and we knew we were going to record another album together, but, in interviews, none of us were going to say it until we actually did it," Hayward said. Midway through the "Octave" sessions, Pinder abruptly dropped out.
"He left the band halfway through the album, and then when we wanted to go out on tour, he decided he didn't want to tour anymore, either," Hayward said. "And, apart from a few letters of business, we haven't had much contact. I just think his priorities became different, whereas mine--and everyone else's--were always music, No. 1. And I still really miss him, because, when I first came into the band, it was our singing and writing that really got us going; we kind of started together."
Still, the Moody Blues weathered the loss quite well, and, with Patrick Moraz, formerly with Yes, they finished the album and returned to the road for a brief tour.
The overwhelming response--"Octave" went platinum and they had no trouble filling multi-thousand-seat arenas--was completely unexpected, Hayward said.
"We never thought we would be able to come back in the same way," he said. "We thought we had been away too long, so we were really making a record for ourselves.
"But then it just took off again--it's like what people couldn't have, they wanted even more."
So the Moody Blues decided to stick with it. Their next album, 1981's "Long Distance Voyager," became their first U.S. chart-topper since "Seventh Sojourn," way back in '72. And, in 1986, with "Your Wildest Dreams," the Moodys scored their first Top 10 single since "Nights in White Satin."
"An amazing thing has happened to us within the last five or six years," Hayward said. " 'Long Distance Voyager' was where it really started to change, into sort of a younger audience, but then with 'Your Wildest Dreams,' having a Top 10 single--which is very rare for the Moody Blues--and a hit video that went along with it, brought a whole new audience to the band that never knew anything about 'Nights in White Satin' or any of that.
"It's weird--this is about two years ago--I was in a bar somewhere, and some guy came up to me, and he was pretty drunk, and he said, 'Aren't you the guy in the Moody Blues video?'
"That's what it's come to--it's almost like we've gotten a second life."
And how long will this second life last?
"I don't know," Hayward said. "I mean, it could finish tonight in Kansas City; it could go on for another 20 years. I've just got no idea. I've got no idea.
"As long as it remains fun and pleasant for all of us, it will go on."