Chicago metal has a strange and not-too-storied history, despite delivering some of the greatest and most influential bands of many metal sub-genres. Anyone who knows anything counts Trouble, Master and Cianide among their favorites. Those who have dug into Paul Speckmann's history give Death Strike & War Cry the respect they deserve on archivist metal blogs. Zoetrope put together some pretty impressive crossover thrash. However, Chicago is currently known for a lot of dumb bands that mistake "experimentation" for creativity, but in the 80s, Chicago was doing it right.
Thrust exists in that nebulous area in the early 80s before thrash metal was a codified genre. This has all kinds of melodic NWOBHM riffs, but is quite a bit more aggressive than even the first two Maiden records. Vocals are bizarrely sing-song in a way that portends the strangeness of Vio-Lence. Each of these songs is a riff fest that traces melodies through linear runs, galloping power chords, and more melodic rock chord progressions. "Speed metal" became something really foolish and cheesy at some point, but these demos showcase what the genre was capable of becoming.