Long before she died on October 4, 1970 at the age of 27, Janis Joplin had been recognised as the original wild child of rock. If her astonishing voice -- part wail, part foghorn, all magic -- didn't draw gasps, her behaviour offstage certainly did.

Now, 34 years later, a documentary describing life on the road with the singer is set for release.

A few months before her death, Joplin travelled from Toronto to Calgary on a train, with icons like the Grateful Dead, Sha-Na-Na and The Band for company. She was the only female star on board what came to be called the 'Festival Express.'

Sixty hours of material shot over five days has been edited and cleaned, supplemented with commentary from surviving band members and journalists, and made ready for a first-time audience.

The fact that Joplin is still a huge figure on the musical landscape decades after her death proves she has become the stuff of legend.

A recent report in The Guardian newspaper discusses how rock would not be the same without her. If Janis hadn't arrived, chances are we wouldn't have had Patti Smith, Björk, Sinéad O'Connor or Courtney Love. She was the one who broke the stereotypes, opening the door to women in rock, holding her own in an industry ruled by men.

Janis Joplin grew up in Texas in the 1950s. She modelled herself on the great blues singer Bessie Smith who, incidentally, had a reputation for living fast and had died at 43. After performing in clubs, Joplin left for San Francisco and won a record contract after well-received performances with her first band, Big Brother and the Holding Company.

Success arrived. Albums followed, as did live performances that won over audiences everywhere. But Joplin was always restless. That she felt compelled to play a role both on and off stage was made obvious in interviews she gave. 'It's not easy living up to Janis Joplin, you know,' she once said.

The world has not forgotten Joplin.

Apart from the documentary, directed by award-winning British filmmaker Bob Smeaton, a biopic on the singer titled Piece of my Heart is due to start filming soon, with actress Renee Zellweger taking on the singer's role.

Interest in her life and her music continues to be intense. Which is justifiable. 'They may not realise it,' Smeaton told The Guardian, 'but all of the women performing today were given a doorway into rock 'n' roll by what Janis Joplin achieved.'