Almost 40 compositions, half of which written for accompanied and unaccompanied choir, can currently be found in the catalogue of works by the young Polish composer Katarzyna Danel (born in 1992). After winning several national composition prizes, she was awarded the 1st prize of the 13th International Composition Competition 'Musica Sacra Nova' 2016 for Misericordias Domini for eight-part mixed a cappella choir. The complex sacred a cappella choral work is based on the eponymous Gregorian chorale (Psalm 89:2). This Latin choral piece is characterized by three main structures: by aleatoric sound clouds in major pentatonic scales which are emphasized by sustained organum-like notes from the Gregorian chorale melody, on the one hand, by Renaissance-style polyphony combined with modern harmony, on the other hand, and finally, by long static chords merging in space and harmony. A wonderfully mystical, spherical composition which, by means of ad libitum passages marked in the musical text, even gives the performer the opportunity to interpret the piece individually.