Crossword puzzle clue "middle school stage commonly"

Middle school stage, commonly

School before middle school: Abbr.

Three-year school, commonly

Elaborate Broadway stage decor, vis-a-vis summer camp theater stage design?

At an early stage — at a late stage

Musician who once changed the middle letter of her stage name to a dollar sign, but later changed it back to a boring old "S"

Middle of a three-stage victory

Middle class resident, in the Middle Ages