Ronnie James DioBefore Ronnie James Dio succumbed to his battle with cancer over a month ago, Heaven & Hell planned to tour. The remaining members -- Black Sabbath's Tony Iommi and Geezer Butler, along with Vinny Appice -- will honor one of their commitments and play a one-off show on July 24 at the High Voltage Festival in London to honor Dio's life, work, voice and heart.

Heaven & Hell were initially scheduled to play to show with Dio. BlackSabbath.com is reporting that former Sabbath and Deep Purple vocalist Glenn Hughes and Masterplan's Jorn Lande will cover vocals in Dio's stead.

Hughes and Dio were lifelong friends, with Hughes performing a tribute to his friend at Dio's funeral service. Lande was a huge Dio fan, even releasing a Dio tribute album.

Proceeds from the July 24 gig will benefit the Ronnie James Dio Stand Up and Shout Cancer Fund. More information on the performance is available at the High Voltage Festival website.