Post-hardcore foursome Thrice seems to revel in pushing boundaries and overturning expectations. The second two-disc installment of THE ALCHEMY INDEX answers VOLS. 1 & 2 (FIRE & WATER) from the first set with VOLS. 3 & 4 (EARTH & AIR). There's little evidence of the ferocious screamo aesthetic that characterized releases like THE ILLUSION OF SAFETY; instead AIR & EARTH ventures into mostly acoustic, highly melodic territory. The tight, technically complex instrumental prowess of the band is still on display, but the mood is much more atmospheric. The songs veer from ethereal and psychedelic to a more conventional folk or singer-songwriter vein (this is especially true of the tracks on the EARTH disc), but the whole adds up to an impressive, original showing from one of the genre's innovators. Their latest shows two more sides of the band that anyone has yet to see. The "Earth" side will showcase a more stripped down, raw element of the band, while "Air" will expose a more soft rock side. Lead single is "Come All You Weary".