One of New Jersey's longest-running underground metal acts, Helmetta's Skitzo have been honing their progressive power and speed metal craft since 1985 — a band whose four decades of persistence speaks to a genuine devotion to the technical, melodic end of the genre.

A separate Santa Rosa, California outfit also formed in 1985, this Skitzo drew from the thrash explosion happening across the Bay Area at the time — capturing the speed and aggression that defined the mid-decade California underground.

Skizofrenia was a thrash metal band from Limache, Valparaíso, Chile, active from 2012 to 2015 before splitting up. The band started as a tribute act before developing original material, playing in Chile's Valparaíso region during their brief run.

Minneapolis's Skjolden, formed in 2025, pursue a melodic black/death metal sound named after a Norwegian fjord village — marrying Scandinavian-influenced melodicism with the intensity of death metal in the tradition of Minneapolis's long-running extreme metal underground.

Wilmington, Delaware's Sklo have been crafting progressive metal with rock-influenced textures since 2009, occupying a corner of the Delaware underground that leans into compositional depth and dynamic range rather than straightforward heaviness.

Colossal Doom / Post-Metal / Shoegaze out of Texas.

SKLP is an industrial metal project from Santiago, Chile, founded in late 2019 or early 2020, drawing inspiration from late 1980s and mid-1990s industrial metal. The project's name is a contraction of the Sanskrit word "sankalpa," reflecting its lyrical focus on self-transformation and the use of music as mantras and audio sigils.

Omaha's Skog (formed 2024) began in atmospheric black metal territory before shifting toward folk and thrash — a restless Midwestern project that draws on Norse woodland imagery and refuses to stay in one sonic lane.

Framingham, Massachusetts' Skog (formed 2024) work a melodic death and black metal hybrid that draws on the fusion traditions common to the Massachusetts underground, pairing Scandinavian-influenced melody with the aggression of American extreme metal.