The Moody Blues, members of rock royalty, play the Belk Theater on Monday

Justin Hayward has had the last laugh. When the Moody Blues singer/composer/guitarist recorded “Nights in White Satin” in 1967, radio stations didn’t know what to do with the four-minute, 21-second song. There hadn’t been anything like it before. “One radio promotions guy resigned rather than promote the song,” Hayward told me from his Atlanta hotel room, where he was staying under an alias. “He said, ‘I can’t do anything with this. No one’s going to be able to dance to it.’ ” Eventually, someone did figure out what to do with the lush (some might say overwrought) love ballad that became one of the first four-minute songs ever to get radio play. It reached No. 1 three separate times on Billboard. “Years after we recorded it, Rolling Stone published a list of the best last songs to play at a prom, and our song was on that list,” Hayward said. “So, I thought: Maybe you don’t even need to dance to it. You just hold on to the person you’re with and stagger about.” You wouldn’t suppose the guy who wrote – at 19 – “Beauty I’d always missed / With these eyes before / Just what the truth is / I can’t say any more / ’Cause I love you” would be a cut-up. But he is. Since he brought up staggering around, I told him I’d seen in my research a lot of references to pharmacological aids being used during his songwriting process. And his songs had been described as music written by people on drugs, for people on drugs. “Oh, is it that obvious?” he asked, tongue in cheek. “I had hoped we’d kept it hidden. “Look, we were part of the London scene in the ’60s,” he said. “I have no regrets.” The Moodies’ most enduring song – with those haunting, cryptic lyrics, hypnotic pacing and singing that becomes almost primal during the chorus – was written on the fly. Hayward had recently joined the group and said he knew they were counting on him to have a song they could record at a session the next day. “A relationship had ended – one that I thought was everything, as you do at 19 – but another one was beginning,” he said of the inspiration for “Nights in White Satin.” “It was an emotional time,” he continued. “But I think there’s a lot of truth – still – in that song: ‘Just what you want to be / You’ll be in the end.’ And the line about letters I’ve written never meaning to send? I do that. I write a lot of letters in the middle of the night that I don’t intend to ever send.” The Moodies’ new spring tour, marking the 50th anniversary of Hayward and John Lodge joining the band, is the “Fly Me High” tour – named for the first single the band released after those two replaced Denny Laine and Rodney Clark in late 1966. Hayward said seven musicians are on stage during these spring concerts – “three of us old guys and four young people.” The concerts are “true to the records,” he said. And they do play favorites. “I think I’d feel cheated if I went to a Moody Blues concert and didn’t hear ‘Nights in White Satin,’ ‘I Know You’re Out There Somewhere’ and ‘Tuesday Afternoon.’ ” When you’ve been together for half a century, the problem isn’t what to play, Hayward said, it’s what to leave out. They “mix it up a bit during the first set,” he said. But the second set is made up of greatest hits. The secret to the band’s longevity? Hayward said, “It comes down to the music, really. We were never celebrities. We didn’t chase after publicity in those early days. I don’t think we smiled in a picture until about 1979.” The Moodies inspired a number of important bands – Yes, Genesis, Jethro Tull. And Hayward said he, in turn, is inspired by a lot of today’s music. He mentioned Ben Rector and South Carolina native Trevor Hall as current favorites and said, “I’ll listen to Kasey Musgrave to cheer myself up.” Fans of the Moody Blues will be cheered by their Charlotte stop. This is a band devoted to its fans. Hayward said, “We’re very lucky to still be working and touring and to have such a strong fan base.”