In English, you can emphasize an important word or syllable by pronouncing it more loudly, as in "It's magNIFicent!" That's not the case in French, which uses the affective accent instead.
The terms "open" and "closed" have two related meanings in regard to pronunciation: open vowels and closed vowels, and open syllables and closed syllables.
The rhythm of French is what makes it such a beautiful language. Thanks to liaisons and enchaînement, French words flow one into the next, and there is no stress on any particular syllable within each word. All of this combines to give French a certain musicality that sets it apart from other languages.