How odd was it for a British band in 1964 to aspire to be a bluegrass band? I couldn't find any other references to such in my research (and I'd be happy to hear from any of my bluegrass pals who know better), but back in '64, Dave Cousins founded The Strawberry Hill Boys. By 1967, however, the band's focus had slowly but surely shifted to their own material, drawing heavily on Cousins' excellent songwriting and strong influences from the rapidly emerging British folk-rock scene. In those days, Sandy Denny (well known for her later work with Fairport Convention and Fotheringay) was a contributing member of the band; they even recorded 13 songs together in 1967, but the band couldn't find a record deal and the album was essentially forgotten until the mid-70s when it was issued in an effort to capitalize on the later successes of both Denny and The Strawbs.
A little piece of music trivia - The Strawbs were the first UK artist to be signed to the very successful A&M (Herb Alpert and Jerry Moss) label. Their first two albums were heavily folk-influenced, and though A&M was an American label, the discs were only released overseas until a double-album re-issue in the States in 1975. The band received strong reviews for their first album which waned a bit with the second; while they played a lot of live shows, their record sales weren't yet impressive. Then the merry-go-round of musicians began. Trying to document the personnel history of the band is a yeoman's task indeed. If it were written in short, you might say that after their second album, Dave and Tony were joined by Rick, Richard and John; Rick was replaced by Blue, then Tony was replaced by another Dave; Richard, John and Blue left to be replaced by a different John, Rod and Chas; the other John and Rod were replaced by Robert and another Tony, though Tony II was replaced soon thereafter by Andy... and that (deep breath) covers the 70s... (Note: there's an excellent personnel history, including a chronological listing and a great visual timeline of the band's players at http://en.wikipedia.org/wiki/Strawbs - there are some amazing names there, but be forewarned... it will take you a while to read it!).
Whether it was due to the constant flux of personnel or the incredibly diverse interests of Dave Cousins (the only constant member of the band), The Strawbs released a series of albums that were of consistently high quality and were well received; as a justified result, their legacy began to grow in earnest. As the founder and only constant in the band, singer/songwriter/guitarist Cousins deserves a lot of attention and acclaim. His talents as both a performer and composer (obviously) span a lot of styles; as a vocalist, he can effectively use a very nasal style which would lend itself to a bluegrass band (and having heard some of the early recordings, they would have been a very good bluegrass outfit), can softly intone a gentler ballad full of emotion or can summon up power and passion when the mood and/or topic of the song needs such. Of course, those vocal talents would be less impressive without superb material to interpret, and Cousins has delivered more than his share of classic tracks to the world of music, another factor in being able to seal his and the band's longevity. It's always nice to have a wealth of acclaimed material to fall back on when you take it back out on the highway.
Once the 70s (and their most successful era, at least as public figures) had passed, the band remained generally active and creative. They essentially disbanded right around 1980, but reunited for an appearance on a Rick Wakeman television show (he's the "Rick" referenced above, by the way), which further resulted in an invitation to reform and headline the 1983 Cambridge Folk Festival. They did, and it was still a very good band. While they never again reached the heights of popularity they achieved during their classic years, the group gigged and recorded occasionally from that point forward. In 1993, they staged a "25th Anniversary Tour" in the UK, had something of a quiet period after that, reprised the success with a "30th Anniversary" bash in 1998 (which I would have LOVED to have seen - several of the bands noted line-ups performing outside on the same day... dayam!), and have, again, toured and recorded with some regularity since. Besides the obvious talent involved, The Strawbs have used their diversity to great results as well; they now perform in two distinct versions, an electric band (essentially the mid to late '70s version of the band) and as an acoustic trio. Since 2006, both versions of the band have toured, they've recorded and released albums and DVDs, they celebrated a 40th Anniversary, and show little sign of losing the desire and ability to continue enchanting a very devoted group of fans.
Then, now, and hopefully always, I put The Strawbs on my short list of Favorite Bands Ever.