Ex-Dream Theater drummer Mike Portnoy is to make a guest appearance with Stone Sour during their set at this year’s Rock In Rio festival.

Stone Sour’s drummer Roy Mayorga will not be appearing with the band at this festival, since he is on sabbatical, since his wife is due to give birth.

Portnoy commented: “It’s an honor and pleasure to be able to help out my good friends in Stone Sour. It’s also an unexpected treat for me to get another visit with some of the greatest fans in the world.”

Plans are still afoot in the Stone Sour camp to release a full-length live DVD and record an EP of cover tunes.  The band have not announced which covers will be included on the EP at this time.