"Eccentric" has been the word used often to describe English singer-songwriter Roy Harper and his music. There might be some truth to that assessment, as Harper's folk-inspired sound isn't exactly commercial or accessible. Lyrically Harper can be very blunt in addressing his views about society on a song such as 'I Hate the White Man,' but yet he can also be also quiet poetic and soulful like on the gentle 'Elizabeth.'

While Harper's musical style and lyrics may account for the lack of greater mainstream acceptance, his name and voice are probably familiar to rock fans. Led Zeppelin recorded the song 'Hats Off to (Roy) Harper' from 1970's 'Led Zeppelin III,' and Harper sang lead on 'Have a Cigar' from Pink Floyd's 1975 album 'Wish You Were Here.' Now his distinct music is being reintroduced to Americans through the recent reissues of his earlier studio albums: 'Flat Baroque and Berserk' (1970), 'Stormcock' (1971) and 'What Ever Happened to Jugula?' (a collaborative album with Jimmy Page, 1985).

So with a musical career that's now in its fifth decade, does Harper, 67, regard the "eccentric" tag as a compliment? "It depends on the tone it's delivered with, isn't it?" he tells Spinner. "I think in a lot of cases it is complimentary. How do you buttonhole me really? There are so many different styles that I've indulged in, and yet to me it's all one style."

In a 1994 interview with folk music publication Dirty Linen, Harper acknowledged someone describing him as "the longest running underground act in the world." "That's because of the very nature of the material," Harper says now. "Not a lot of people right at the beginning of my career were listening to songs that were 20 minutes long. Just after I've done that, things like [Led Zeppelin's] 'Stairway to Heaven' were popularized longer songs. If I had arrived four years later I would've been part of the mainstream now."

Having known Led Zeppelin from their London days, Harper remembers a visit to the band's office when Jimmy Page handed him a copy of 'Led Zeppelin III,' which has the song 'Hats Off to (Roy) Harper.' Harper casually put the album under his arm. "[Jimmy] said, 'You haven't looked at it yet,'" he says. "So I then I started to look at it and then I saw my name on it. I said, 'Uh, um, thanks.' They were mildly amused. It's been a milestone and a great joy all in one."

For Pink Floyd's 'Have a Cigar,' Harper's involvement happened by chance. Both acts were working separately at London's Abbey Road studios, and Harper was at one of the Floyd's sessions. He says that the band members were frustrated with the song to the point of them almost throwing it away.

"So I said from the back of the studio," Harper recalls, "'I'll do it for you [for a price].' Roger [Waters] said, 'What's the price then?' I thought, 'OK, I'll go for a season ticket to Lord's [a cricket ground in London] for life.' And he agreed. It never came, and that is a sore point between Roger and I, but not between Dave [Gilmour] and the rest."

In his career, Harper had no problems lining up major artists to collaborate with him such as Paul and Linda McCartney, and Kate Bush. These days his music has been respected by future generations of musicians. In a Guardian newspaper article, former Smiths guitarist Johnny Marr praised 'Stormcock,' and last year, Harper opened for Joanna Newsom at London's Royal Albert Hall.

Currently residing in Ireland, Harper had resumed writing and recorded five songs though he is unsure what will come out of that. He took some time off from performing while recovering from prostate cancer. "I'm not saying that I won't tour again," he says. "If I do get a bite from the USA, maybe I'll get it together, come over there and have me a ball, sort of speak."