Tool's dense, often quasi-religious lyrics have always been among the most overwrought in mainstream metal — no small feat. But the music has such anthemic power that even the most cynical listener can find himself chanting along to lines like "To ascend, you must die!/You must be crucified!"

On 10,000 Days, their fourth album, Tool maintain a level of craftsmanship and virtuosity unparalleled in metal. On the opener, "Vicarious," the quartet reprises its primary formula, which dates back to the 1993 debut, Undertow: Each player keeps his own syncopated version of the central groove until they unite for the first of many spine-tingling crescendos — then, just as sharply, the foursome de-crescendos into a brooding instrumental jam, as the rhythmic and melodic lines meander and cross until the next explosion. The web of shifting dynamics and time signatures sounds so primal, so visceral, that any lyrical message seems incredibly important.

Singer Maynard Keenan's operatic vocals, alternately simmering and shrill, are more personal and less pretentious here than ever before. The album title refers to the time between when Keenan's mother became paralyzed in the 1980s and when she died, in 2003, an experience that inspires some of Keenan's most poignant lyrics yet ("10,000 days in the fire is long enough/You're going home"). More than fifteen years into Tool's career, he has composed words with the depth and resonance to match the music.

“Is It True”

As the British Invasion reached its peak in 1964, Brenda Lee went from Nashville to London to record one of her hardest-rocking hits, her perky vocal backed by a stuttering, squalling guitar. That guitar was played by session musician Jimmy Page, yet to skyrocket to fame with first the Yardbirds and then Led Zeppelin. "She said to me, 'I've come here to make a record with the British sound,'" remembered producer Mickie Most. "She felt she wouldn't get the same sound in Nashville because they're only just catching up on the British beat group sound of about six months ago."