Within the Ruins is a metal-core / death-core / I get-lost-in-all-the-sub-genres-don't-pick-on-me / progressive band hailing from Massachusetts, with 6 studio albums under their belts as well as a few EPs.
Their instrumental series, "Ataxia" is your pick for the week. Five total versions, with the 5th version out late last year.
Here, let me give them to you all out of order. "Ataxia II" is my favorite.