Jonkal is a guitar artist from Athens, Greece, born in 1989, creating metal instrumentals that showcase technical guitar proficiency. His release This Fight is My Own demonstrates his approach to heavy guitar-driven compositions within the Greek metal scene.

Josh H is a metal and post-punk musician from Spain whose recordings span multiple heavy genres with an eclectic, genre-bending approach. His work bridges the gap between aggressive metal and dark post-punk atmospherics, drawing on influences from both sides of the heavy music spectrum.

Jotungrav is a Finnish progressive folk metal project centered on extended compositions about Nordic mythology examined through modern philosophical perspectives. Founded as a solo venture by singer/songwriter Matias Stenman, the project expanded in 2023 with drummer Matias Rokio, crafting ambitious tracks that stretch around the ten-minute mark.

Joviac is a progressive metal band from Tampere, Finland, influenced by a broad spectrum from AOR to jazz. Their approach combines the compositional freedom of progressive music with addictive hooks, blending catchy riffs and melodies with conceptual depth across releases like Autofiction Pt. 1 - Shards.

Juan Martin JG6 is an instrumental metal guitarist from Terrassa, Spain, whose releases including The Fairy of Eagle Nebula and Guitar Farm showcase technical guitar work with cosmic and atmospheric themes. His compositions blend progressive metal precision with ambient and spacey textures.

Juglans Regia is a rock, progressive, and heavy metal band from Florence, Italy, established in 1992 with a current five-piece lineup. Their fifth album Neranotte (2023) continues over three decades of blending progressive structures with heavy metal power across multiple lineup changes.

Juodvarnis is a progressive metal band from Vilnius, Lithuania, whose Lithuanian-language albums including Tekmes and Nerimo Dienos explore heavy music through a distinctly Baltic lens. The band performs at major festivals including Kilkim Zaibu and maintains an active presence in the Lithuanian metal scene.

Just is a heavy metal band from Hungary that delivers aggressive, hard-hitting compositions rooted in the Central European metal tradition. Their approach to heavy music channels the energy and intensity that characterizes Hungary's growing metal scene.

Juvaliant is a symphonic progressive power metal band from Salzburg, Austria, whose name fuses the city's Latin name Juvavum with the word valiant. Their debut album Inhuman Nature (2010) was released through Limb Music with artwork by Felipe Machado Franco, known for his work with Iced Earth and Ayreon, and addresses weighty themes of war, terror, and discrimination through dramatic orchestral metal.