Losing a lead singer can be incredibly disruptive for a band.

Some bands will bounce back -- AC/DC, for example, sounded better than ever when they hired Brian Johnson after Bon Scott's untimely death -- while others will suffer a creative decline.

Sepultura experienced a major loss when former lead singer Max Cavalera left to form Soulfly in 1996, but thankfully, Derrick Green proved to be a highly capable replacement.

If 1998's mildly uneven Against -- Sepultura's first album with Green -- found the band struggling with the transition, Green was filling Cavalera's shoes much more confidently on 2001's Nation.

And if there are still any lingering doubts about the Green/Sepultura match, 2003's excellent Roorback should put them to rest for good.

Green is passionate and focused throughout the album -- he has no problem going that extra mile -- and the writing is consistently strong.

Unrest and political corruption are recurring themes on Roorback; American singer Green and his Brazilian colleagues spare no anger on incendiary tracks like "Mind War," "Apes of God," and the crushing opener, "Come Back Alive" (which is about surviving the horrors of wartime combat).

The songs that Sepultura wrote for Roorback paint a consistently bleak and troubling picture of the world -- one that is only reinforced by an unlikely remake of U2's "Bullet the Blue Sky" appended to the album.

Sepultura successfully give U2's gem a ferocious alternative metal makeover, and Bono's dark lyrics are right at home on this politically charged CD.

When Roorback came out during the summer of 2003, Sepultura had been together for 19 years -- and this compelling disc finds them very much on top of their game after almost two decades in the metal field.

[Upon its initial release, Roorback included the Revolusongs EP, which included several covers, among them U2's "Bullet the Blue Sky," Jane's Addiction's "Mountain Song," and Massive Attack's "Angel."].