Complex sentence: Principally recorded by Nico, Gregg Allman, and Browne himself in three different musical worlds, it has lasted for decades as a classic of morose introspection made even more remarkable by Browne having been only 16 years old when he wrote it.
Split into simpler sentences: Principally recorded by Nico, Gregg Allman, and Browne himself in three distinctly different musical styles. The song has endured for decades as a classic of morose introspection, made all the more remarkable by Browne having been only 16 years old when he wrote it.