John Stewart recorded some of pop music's most acclaimed solo albums, helping create a style that came to be called Americana, but he was always best known for writing the Monkees' enduring hit "Daydream Believer."Stewart, who came to prominence in the 1960s as a member of folk music's Kingston Trio, died Saturday at a San Diego hospital after suffering a brain aneurism. He was 68."He was a lovely man and a very gentle soul and I guess the only thing you can say today is that the world is less one great songwriter," the Monkees' Mickey Dolenz told The Associated Press on Sunday.Stewart left the Kingston Trio shortly before the Monkees released "Daydream Believer" in 1967, then went on to record nearly four dozen solo albums, including the critically acclaimed "California Bloodlines" and "Bombs Away Dream Babies." The latter included the hit single "Gold," in which he dueted with Fleetwood Mac's Stevie Nicks.Still, as with "Daydream Believer," he was likely best known for writing songs for others, including Joan Baez, Nanci Griffith, Roseanne Cash and Anne Murray."He was a cult hero, he never made it super huge," said his manager, Dean Swett. "He was one of those outlaw rebels, one of the people who refused to conform to what the record labels expected him to be."A husky-voiced singer and accomplished guitarist who delivered his lyrics in a poignant, often longing voice, his music was hard to classify. It fell somewhere between rock, country and folk and eventually came to be called Americana.He wrote "Runaway Train," a country hit for Roseanne Cash, and "Strange Rivers," which Joan Baez included on her 1992 "Play Me Backwards" album. Nanci Griffith dueted with him on "Sweet Dreams" and Murray, like the Monkees before her, had a hit with "Daydream Believer.""There are certain songs that you just go in humming. It was one of those," Dolenz said of "Daydream Believer," which also was Stewart's best-known recording. Although he sang background to Davy Jones' lead on the Monkees' version, Dolenz performs the song himself at his solo shows."To this day it is one of the biggest songs that I do in concert," he said.Stewart joined the Kingston Trio in 1961, replacing Dave Guard in the group that had helped usher in an American folk music revival in the late 1950s."John truly was the right fit. A first rate entertainer and gifted songwriter," the group said in a statement on its Web site.He recorded more than a dozen albums with the trio before going on to a solo career in 1967. A year later he released "California Bloodlines," which included the minor hit "July You're a Woman." "Bombs Away Dream Babies" came out in 1979.He eventually recorded more than 40 solo albums. Others included "The Lonesome Picker Rides Again, "Airdream Believer" and "Rough Sketches," the latter a collection of songs about the iconic American highway "Route 66."Stewart was said to be at work on still another album at the time of his death.Stewart's wife, Buffy, and children were at his side when he died, according to a statement on the Kingston Trio's Web site. There was no immediate word on funeral arrangements.