The translation of the German titles means both “mirror in the mirror” and “mirrors in the mirror

The translation of the German titles means both “mirror in the mirror” and “mirrors in the mirror,” and this refers to the abundant images that are produced by parallel plane mirrors. Within the music, this sense of mirroring is achieved by the fragmented sections in the piano, which are continuously repeated with little variations, creating the illusion of being reflected back and forth. The repeating piano part also reiterates the violin’s melodic line by using parallel thirds and octaves, while additional voices are revealed from the core note, which is A. the underlying and ever-present tonality of the piece is F major, the key in which it was composed. (Anonymous, 2012)
The piano part of Spiegel im Spiegel carries the Tintinnabuli line which consists of repeated arpeggiated chords as well as low, legato Fs in the bass. An interesting texture is created throughout the piece by the high, bell-like sounds occurring in the upper registers. The melodic line is slow and ascending and begins with a G-to-A scale of two notes, which also descends to A by step. With each movement, another note is added to the line, a process which could progress open-endedly and resembling the “mirror in mirror” imaging. A sense of pure tranquillity is created through the continuity and ongoing inversion of the melodic line combined with the piano part. The music contains no ambiguity or tension as the listener can feel that the music will always return to the A pitch. The emotional quality evoked by this piece stems from the atmosphere created by the pure sonorities and simplicity of the piece. (Anonymous, 2012)
Arvo Pärt does not give any dynamic or phrase markings – the melodic line is particularly blank, and it would still sound effective even if one were to play it in a completely flat manner. However, a musician has an instinctual tendency to alter the level of dynamics as the music rises. The piece ends almost identically to how it begins: with a repeated motif in the piano part partnered with the sustained A in the melodic line. It ends with a soft ritardando in the final bar. (Anonymous, 2012)
Although the notes played are not particularly difficult, it is important to establish a fitting tempo for the piece, for if it is played too slowly, there is a risk of it sounding too heavy. The main task is then to set correctly the mood of the implied reflections, so that the notes sounds like water dropping into water, and the notes must be played as beautifully as possible. The music ultimately plays itself: it does not need to be over-interpreted. (Anonymous, 2012)