As a musician, Harper is known for his distinctive fingerstyle playing and lengthy, lyrical, complex compositions, reflecting his love of jazz and the poet John Keats.

"[3] Neil McCormick of The Daily Telegraph described him as "one of Britain's most complex and eloquent lyricists and genuinely original songwriters... much admired by his peers".

[4] Across the Atlantic, his influence has been acknowledged by Seattle-based acoustic band Fleet Foxes, American musician and producer Jonathan Wilson, and Californian harpist Joanna Newsom, with whom he has also toured.

After two years Harper rejected the rigid discipline and feigned madness to obtain a military discharge, as a result receiving an electroconvulsive therapy treatment at Princess Mary's RAF Hospital, Wendover.

Of the blues musicians Lead Belly, Big Bill Broonzy, and Josh White, Harper said they made music which "...seemed to be from a different planet ...We'd never heard anything like it.

He obtained a residency at London's famous Soho folk music club Les Cousins in 1965, having been introduced to it by Peter Bellamy of The Young Tradition.

The album consisted of Harper's songs and poetry backed by acoustic guitar, recorded with a Revox tape machine by Pierre Tubbs and with contributions from English guitarist Paul Brett.

In June 1968, Harper performed at the first free concert ever held at Hyde Park, acting as compere and sharing the bill with Jethro Tull, Pink Floyd and Tyrannosaurus Rex.

The album was released in the UK, the Netherlands, Germany and a number of other European countries as part of an international marketing campaign by Columbia Records (known in Europe as CBS).

The track "Sergeant Sunshine" would also appear on Son of Gutbucket, a 1969 sampler album released to promote artists on the Liberty Records label.

Kalvik would later go on to record Norwegian versions of two Harper songs; "I Hate the White Man" ("Den hvite mann") and "Don't You Grieve" ("Kjære ikke gråt").

With Harper's reputation growing, Pink Floyd's former manager Peter Jenner signed him to a long-term (and at times confrontational) deal with EMI's 'underground' subsidiary, Harvest Records.

The album also featured the Nice on the track "Hell's Angels"; its ethereal sound achieved by a wah-wah pedal attached to Harper's acoustic guitar.

In mutual appreciation of their work, Harper would often attend live performances by Led Zeppelin over the subsequent decade and contributed sleeve photography to the album Physical Graffiti.

Thirty-five years later (in 2006) fellow Mancunian Johnny Marr of English alternative rock band the Smiths said: If ever there was a secret weapon of a record it would be Stormcock...

At the time, Lifemask was created as Harper's final bow, as he had been diagnosed with the (then) little-known genetic condition HHT, which caused polycythemia, incapacitating him.

A concert to mark its release was held on the same day at London's Rainbow Theatre, with Led Zeppelin's Jimmy Page, Robert Plant, and John Bonham;[25] David Bedford, Max Middleton, Ronnie Lane, and Keith Moon performing alongside Harper.

David Gilmour returned the favour by appearing on HQ, along with Harper's occasional backing band, 'Trigger' (Chris Spedding, Dave Cochran, Bill Bruford and John Paul Jones).

In April 1978, Harper began writing lyrics for the next Led Zeppelin album with Jimmy Page, but the project was shelved when lead singer Robert Plant returned from a break after the death of his son, Karac Pendragon.

During this period, Harper spent considerable time in the United States and signed with the US division of Chrysalis Records, who released HQ under a different title – When an Old Cricketer Leaves the Crease – and with alternative artwork.

[24] During a BBC Radio interview by Paul Gambaccini, Bush praised Harper, stating: Roy is one of the greatest English songwriters we've had, and people just don't realise it.

Throughout 1984, Harper toured the United Kingdom with Jimmy Page performing a predominantly acoustic set at folk festivals under various guises such as the MacGregors, and Themselves.

[41] Throughout the decade, Harper's musical influence began to be recognised by a younger generation of musicians, some of whom covered his songs or invited him to make guest appearances on their albums.

In 1995 Harper contributed spoken words on the Tea Party's 1995 album The Edges of Twilight, and appeared on stage for their New Year concert in Montreal.

[44] Views of procreation, his mother's continued presence in him and something of his psychological impulses are punctuated by a couple of moments of satire,[45] a love song and a lament, followed by the lengthy "These Fifty years", of which he has said, "In some ways its (anti-organised religion) theme is similar to 'The Same Old Rock', but in many others I think it's stronger".

In 2000, Harper released an almost entirely acoustic album, The Green Man, accompanied by the Tea Party's Jeff Martin on guitar, hurdy-gurdy and numerous other instruments.

The package also includes an additional 10-track audio CD and received a 4-star review from Mojo, Uncut, and Classic Rock magazine, who made it their "DVD of the month".

The album, What You Need Is What You Have, The Songs of Roy Harper was being compiled by Laurel Canyon folk singer, musician and producer Jonathan Wilson, and was to feature Chris Robinson (the Black Crowes), Gary Louris (the Jayhawks), Johnathan Rice, Eric D. Johnson (Fruit Bats, the Shins), Benji Hughes, Will Oldham, Andy Cabic, Dawes, Jenny O., Josh Tillman and others.

The award itself was presented by longtime collaborator and friend, Jimmy Page and now hangs upon the wall at De Barras Folk Club in Clonakilty, Ireland.

[69] Following police interviews in February 2013, Harper was charged in November 2013 with ten counts of alleged historical child sexual abuse over a period of several years with an under-age female.