For the first six months, the group continued doing the R&B-based repertory that they'd been known for prior to Hayward's arrival. Gradually, however, they began to work new songs into their stage act and their recording schedule, which took a big jump when the group was picked by Decca/London Records to participate in a stereo-demonstration record mixing rock and orchestral sounds. The resulting album, Days of Future Passed (1967), revived the band's fortunes, not least through the success of a Justin Hayward song called "Nights in White Satin." Although Hayward proved he could also rock out, he quickly became established as the romantic/mystic of the band, known not only for "Nights in White Satin" but songs such as "New Horizons" and "Your Wildest Dreams."

Hayward's career as a solo artist began in 1977 with the release of Songwriter, which displayed a somewhat leaner and more lively, acoustically textured sound than his work with the Moody Blues. He followed this up in 1980 with Night Flight, a major departure from his work with the group, with very much of a belated disco sound. During the next several years, Hayward devoted much of his attention to the revived Moody Blues, who had a full touring and recording schedule in front of them. His Moving Mountains (1985) was strongly reminiscent of his earlier work with the band from the start of the 1970s. Since then, when he is not working with the band and writing new material (his "Your Wildest Dreams" reached number nine in America in 1986), Hayward seems to devote his time to reviving older Moody Blues songs in solo settings, as on the 1994 release Classic Blue in which he sings Moody Blues songs with orchestral accompaniment. A guitarist of great skill and a unique sound, Hayward remained one of the few stars of the 1960s who retained a devoted international following into the 1990s, though most critics -- as with the Moody Blues -- had ceased to consider him a serious contemporary artist.