As Florian Fricke moved away from an early synthesizer-centered sound and embraced organic instrumentation in his quest to fuse Eastern and Western musical and spiritual traditions, Popol Vuh's rock orientation became more pronounced.

That aspect derived largely from the contributions of electric guitarists Conny Veit (on Hosianna Mantra and Seligpreisung) and Daniel Fichelscher (on Seligpreisung, Einsjäger & Siebenjäger, and Das Hohelied Salomos).

Letzte Tage - Letzte Nächte is the band's boldest foray into rock territory.

On Das Hohelied Salomos, Fichelscher's guitar often eclipsed Fricke's piano; here, his presence is even more emphatic.

That's not to say that the band has lost its equilibrium -- this is another classic Popol Vuh exercise in balancing and reconciling apparent opposites.

An opening pair of instrumentals sets the tone.

Buoyed by hard-driving percussion, on "Der Große Krieger" Fichelscher combines muscular riffage with a lightness of touch as he unleashes streams of soaring notes; "Oh Wie Nah Ist der Weg Hinab" builds on an ominous Floydian groove before lilting, interwoven guitar lines lift the song to its conclusion.

Elsewhere, vocals play a key role in the dynamics: pounding drums and thick layers of bluesy guitar provide a heavy foundation on "Dort Ist der Weg," while the ethereal voices of Djong Yun and Renate Knaup add an expansive dimension.

Their vocals also contribute a pastoral feel, especially on the folky title track and on meditative numbers like the guitar and piano mantra "Haram Dei Raram Dei Haram Dei Ra" and "Kyrie," on which Fricke's arpeggios blend with Ted de Jong's tamboura and Alois Gromer's sitar.

Concluding a strong cycle of albums, Letzte Tage - Letzte Nächte continues to encapsulate Popol Vuh's defining characteristics: an ability to create music that's simultaneously delicate and powerful, detailed and expansive, earthbound in its origins and cosmic in its reach.