In 2020, Fefolt was invited by Swedish guitarist and book author, Janne Stark, to contribute vocals on 'Volume Four' of his ongoing Mountain of Power cover project. Fefolt can be heard on a medley of Riot's "Overdrive" and "Do It Up" as well as "You Got My Soul" by Dirty Tricks. The album was released November 27, 2020 on Grooveyard Records. 