Fratres (meaning "brothers" in Latin) is a musical work by the Estonian composer Arvo Pärt exemplifying his tintinnabuli style of composition.
[1] It is three-part music, written in 1977, without fixed instrumentation and has been described as a "mesmerizing set of variations on a six-bar theme combining frantic activity and sublime stillness that encapsulates Pärt's observation that 'the instant and eternity are struggling within us'".
[2] Structurally, Fratres consists of a set of nine chord sequences, separated by a recurring percussion motif (the so-called "refuge").
The generated chords create harmonic ambiguity, since both C# and C are present, yielding an A major or A minor feel.
Although often performed by violin and piano, versions for larger ensembles, such as a string quartet or chamber orchestra, are also common.