A lot has changed for Flyleaf since we first heard Lacey Sturm's throat-shredding bellows on the band's breakout hit, "I'm So Sick," in 2005. The most notable is that she no longer is the band's singer, having stepped down in October, a week before the band's latest album, New Horizons, was released. Former Vadera singer Kristen May now leads the band, and the two are quite different performers. May employs a subtler, more melodic tone to her vocals. She's made a valiant effort to keep Flyleaf fans interested, but it's difficult to simply replace the woman who gave us the propulsive "Again" and the crunchy "Beautiful Bride," especially when fans have been so devoted to Sturm and the spirit she brought to the band. Abrasive New Horizons numbers like "Fire, Fire" and "Call You Out" are not in May's vocal wheelhouse, but parts of the album — namely the title track and "Stand" — are right up May's alley, reflecting the band's continued move away from the metal sound of their debut into the modern-rock realm. Flyleaf is trying to evolve, but can May lead the way?