Arcade Fire at the Pepsi Center, 4-23-14 (photos, review)

If Win Butler is the frontman or the brain of Arcade Fire, Régine Chassagne is the band’s heart. As a “deathly ill” Butler did his best to sing through some of his more demanding songs at the Pepsi Center on Wednesday, Chassagne charmed and pushed her backing vocals from pleasant embellishments to frontwoman status -- picking up the reins like any good band member, partner or wife would do.