Complex sentence: M-Base (short for "macro-basic array of structured extemporization") is a concept of how to create modern music which reached its peak in the mid-to-late-80s and early 90s.
Split into simpler sentences: M-Base (short for "macro-basic array of structured extemporization") is a concept of how to create modern music. It reached its peak in the mid-to-late-80s and early 90s.