After Atlanta Ballet’s new artistic director, Gennadi Nedvigin, took over last year, five of the company’s dancers (including one who had applied for Nedvigin’s position) decided to split off and form Terminus Modern Ballet Theatre, which gives its first performances this month. “While American ballet tends to emphasize youth and athleticism, [John] Welker and the rest of the Terminus five envisioned a company that would showcase more mature dancers as artists capable of creating nuanced and poignant moments on stage.”