Fans of the late Johnny Hallyday, "the French Elvis Presley", will be able to commemorate the sixth anniversary of his death with two songs never released before.

Hallyday, blessed with a powerful husky voice and seemingly boundless energy, died in December 2017, aged 74, of lung cancer after a long career mostly dedicated to covers of American rock'n'roll, and partly to acting in film.

After an estimated 110 million records sold during his lifetime -- making him one of the world's best-selling singers -- Hallyday's success has continued unabated beyond his death.

Almost half of his current listeners on Spotify are under the age of 35, according to the streaming service, and a posthumous greatest hits collection of "France's favourite rock'n'roller", whose real name was Jean-Philippe Leo Smet, sold more than half a million copies.

The two new songs, "Un cri" ("A cry") and "Grave-moi le coeur" ("Engrave my heart"), are featured on two albums published by different labels which also contain already-known hits in remastered or symphonic versions.


'Like playing with my buddy,' Yodelice said / © AFP

"Un cri" was written in 2017 by guitarist and producer Maxim Nucci -- better known as Yodelice -- who worked with Hallyday during the singer's final years.

At the time Hallyday had just learned that his cancer had returned, and he "felt the need to make music outside the framework of an album", Yodelice told reporters this week.

Hallyday recorded a demo version of the song, accompanied only by an acoustic blues guitar, but never brought it to full production.

Sensing the fans' unbroken love for Hallyday, Yodelice decided to finish the job.

He separated the voice track from the guitar which he felt was too tame, and arranged a rockier, full-band accompaniment.

"It felt like I was playing with my buddy," he said.

The second song, "Grave-moi le coeur", is to be published in December under the artistic responsibility of another of the singer's close collaborators, the arranger Yvan Cassar.

Hallyday recorded the song - a French version of Elvis's "Love Me Tender" -- with a view to performing it at a 1996 show in Las Vegas.

But in the end he did not play it live, opting instead for the original English-language version, and did not include it in any album.

"This may sound crazy, but the song was on a rehearsal tape that had never been digitalised," Cassar told AFP.

The new songs are unlikely to be the last of new Hallyday tunes to delight fans, a source with knowledge of his work said.

"There's still a huge mass of recordings out there spanning his whole career," the source said.