Swedish hard rock quartet Greenleaf offer a filthy-sounding brand of stoner and sludge metal combined with riff-heavy, '70s-influenced hard rock. They were formed as an informal side project for members of Dozer and Demon Cleaner. Despite many personnel changes over the years -- guitarist Tommi Holappa remains the only original member -- their sound has remained remarkably consistent. The group issued three fine albums for Small Stone including 2003's Secret Alphabets and 2007's Agents of Ahriman. They became a full-time recording and touring band in 2010. 2014's Trails & Passes is widely considered their finest album. Greenleaf signed to Napalm Records for Rise Above the Meadow, and 2018's Hear the Rivers marked their first outing with vocalist Arvid Hällagård. 2021's Echoes from a Mass made global streaming and European album charts.