Progressive Doom is a Doom Metal subgenre that combines typical Doom Metal components with progressive rock and metal. Slow, heavy riffs, typically with intricate time signatures and patterns, characterize it, and it frequently incorporates elements of jazz, classical, and folk music. The lyrics are frequently dark and introspective, with voices that are deep and guttural. Progressive Doom is frequently regarded as a more experimental and progressive kind of Doom Metal, serving as a link between traditional Doom Metal and more progressive metal.