This is a magical album where so much is said with so little, and often at a daringly low volume. Two versions of “Für Alina”—drawn from a seven-hour improvisation by pianist Alexander Malter on Pärt’s original piece—separate three versions of Pärt’s classic “Spiegel im Spiegel,” shared between violin and piano and cello and piano. The power of this deceptively simple music lies in its delicacy and its clever juxtaposition of minor and major keys, creating a kind of microclimate where everything operates in miniature. It’s a recording that works its way under your skin and never leaves.