Complex sentence: The earliest bands of this (sub-) genre include forefaters of horror punk The Misfits, when they released Earth A.D. it featured sets of songs that were faster (or "Thrashier") than their standard sound of their first two albums.
Split into simpler sentences: The earliest bands of this (sub-) genre include forefathers of horror punk The Misfits, when they released "Earth A.D". It featured sets of songs that were faster (or "thrashier") than their standard sound of their first two albums.