Their second single "Go Now", with Denny Laine on lead vocals, was released in November of 1964 and fulfilled every expectation and more, reaching #1 in England. In America, it peaked at #10. After touring Britain with Chuck Berry, The Moody Blues traveled to the United States, supporting The Kinks. Finding a second hit was easier said than done. Despite their fledgling songwriting efforts and the access they had to American demos, this early version of The Moody Blues never came up with another single success. By the end of the Spring of 1965, the frustration was palpable within the band. The group decided to make their fourth single, "From The Bottom Of My Heart", an experiment with a different sound. Unfortunately, the effort only reached #22 on the British charts following its release in May of 1965. Ultimately, the grind of touring coupled with the strains facing the group, became too much for Warwick, who exited in the spring of 1966, and by August of that year Laine had left as well. Warwick was replaced by John Lodge. His introduction to the band was followed in late 1966 by the addition of Justin Hayward.

The reconstituted Moody Blues set about keeping afloat financially, mostly playing in Europe, recording the occasional single. Their big break came from Deram Records, an offshoot of their Decca label, which in 1967 decided that it needed a long-playing record to promote its new Deramic Stereo. The Moody Blues were picked for the proposed project, a Rock version of Dvorak's New World Symphony, and immediately convinced the staff producer and the engineer to abandon the source material and permit the group to use a series of its own compositions that depicted an archetypal day, from morning to night. Using the tracks laid down by the band, and orchestrated by conductor Peter Knight, the resulting album "Days of Future Passed" became a landmark in the band's history. The mix of Rock and Classical sounds was new, and at first puzzled the record company, but eventually the record was issued. The album propelled the group to stardom. It stayed on the Billboard chart for over two years and marked a milestone in Rock history as one of the very first concept albums, recorded not only with a symphony orchestra, but also in stereo, both uncharted territory at that time. Thanks to the singles "Tuesday Afternoon" (#24 in 1968) and "Nights In White Satin" (#2 in 1972) the record eventually went Gold, reaching #3 in the charts.

Their 1968 follow-up, "In Search Of The Lost Chord" was equally successful, pioneering the use of the mellontron in Pop music, a synth-like instrument which became a key part of their sound. By the time of 1969's "To Our Children's Children's Children", the group found themselves painted into something of a corner. Working in the studio with the process of overdubbing, they'd created albums that were essentially the work of twenty or thirty Moody Blues. Beginning with "A Question of Balance" (1970), the group made the decision to record albums that they could play in concert, reducing their reliance on overdubbing and toughening up their sound. The new, more stripped-down version was even more popular with fans, and the album went to #1 in Britain and #3 in America. "Every Good Boy Deserves Favour", a 1972 album named after a music theory mnemonic, and 1973's "Seventh Sojourn" were even more popular, reaching #1 in the U.S. and the U.K. By then, the strain of touring and recording steadily for five years was beginning to take its toll, and following an extended international tour, the band decided to take a break from working together, which ultimately lasted five years. During this era, Hayward and Lodge recorded a very successful duet album, "Blue Jays" (1975), and all five members did solo albums. By 1977, however, the group members had made the decision to reunite, a process complicated by the fact that Pinder had moved to California during that period. Although all five participated in the resulting album, "Octave" (1978), there were stresses during its recording, and Pinder was ultimately unhappy enough with the LP to decline to tour with the band. The reunion tour was a success however, with Patrick Moraz brought in to replace Pinder on the keyboards, and the album topped the charts.

The group's follow-up record, "Long Distance Voyager" (1981), was even more popular, though by this time a rift was beginning to develop between the band and the critics. Although they continued to reach the middle levels of the charts, and even had a #9 hit in 1986 with "In Your Wildest Dreams" and "The Other Side Of Life" (#11 on the Adult Contemporary chart), The Moody Blues were no longer anywhere near the cutting edge of music. By the end of the 1980s, they were perceived as just another nostalgia act, albeit one with a huge audience. Moraz left the band in 1990, prior to the recording of "Keys Of The Kingdom", but The Moody Blues marched on into the '90s with the comforting knowledge that they still had the ability to fill concert halls. In 1994, a four-CD set called "Time Traveller" was released. In the Spring of 1997, PolyGram released re-mastered and upgraded versions of all seven of the group's classic late 1960s/early 1970s albums, with dramatically improved sound and new notes featuring recollections by the group members. A new studio effort, "Strange Times" followed in 1999 and "Live at the Royal Albert Hall 2000" followed a year later.

The new millennium saw The Moody Blues cut back their tour schedule. Two years later, founding member Ray Thomas retired from the group, reducing the band to the trio of Hayward, Lodge and Edge, the latter being the only original member remaining. Flautist and rhythm guitarist Norda Mullen was brought in early 2003 for their North America tour, and continued to work with the band. Toward the end of the year, they released a holiday album entitled "December". The songs included originals and four covers such as John Lennon's "Happy Xmas (War Is Over)", Mike Batt's "A Winter's Tale", "When A Child is Born" and even a version of Bing Crosby's "White Christmas". In March 2006, the first five of the band's seven essential albums from "Days Of Future Passed" to "Seventh Sojourn" were re-released. In April 2007, the final two of the set were re-issued by Universal /Threshold. On May 21st, 2007 the Moodies released a forty-one track, two-disc compilation of sessions recorded at BBC Studios, various television appearances and a performance from the Tom Jones show titled Live at the BBC: 1967-1970. In September 2008, Justin Hayward announced the release of re-mastered versions of "Octave", "Long Distance Voyager" and "The Present", on Universal Records.

The group continued to tour America, Canada and the UK in 2009 and 2010, with the band adding keyboardist Alan Hewitt in 2010. 2012 was filled with shows scheduled across the United States, wrapping up on December 15th. In early December, singer-guitarist Justin Hayward announced plans for a fourteen song solo album to be released in 2013. The Moodys' plans for the Spring of 2016 included a month-long series of dates across the U.S. That series of shows was later extended into early 2017. In December of that year, Cleveland's Rock and Roll Hall of Fame announced that The Moody Blues' classic lineup of Thomas, Hayward, Edge, Lodge and Pinder, would be inducted as part of the Class of 2018. The Hall corrected an oversight a few days later when Denny Laine was also awarded the honor. Sadly, Ray Thomas passed away on January 4th, 2018 at the age of 76 after a three year battle with prostate cancer.

After the COVID-19 pandemic canceled virtually all shows for 2020 and much of 2021, bassist John Lodge was not optimistic about the band returning to the stage. "I don't think there'll be anything with the Moodys," he said from his home in Naples, Fla., where he spent a lot of his down time writing and recording new material. "I know the Moodys won't tour again. I would tour, but I know Justin [Hayward] doesn't want to tour with the Moodys, so it won't happen." Lodge added that he's not too happy about it, "but it's life, you know." He added, "When I tour, I just play all Moody Blues songs because I want to keep it alive and fresh."

On November 11th, 2021, the family of drummer and Moody Blues co-founder Graeme Edge announced that he had passed away at the age of 80. After the news broke, Justin Hayward wrote on Facebook, "When Graeme told me he was retiring, I knew that without him it couldn't be the Moody Blues anymore. And that's what happened. It's true to say that he kept the group together throughout all the years, because he loved it."

The band's former guitarist, Denny Laine passed away on December 5th, 2023 at the age of 79.

The last surviving member of the band, Mike Pinder, died peacefully at his home in California on April 24th, 2024. He was 82.

For more, be sure to read Gary James' interviews with Mike Pinder and Justin Hayward