XY Quartet is a musical ensemble formed by Nicola Fazzini on alto saxophone, Alessandro Fedrigo on electric bass, Saverio Tasca on vibraphone, and Luca Colussi on drums. The quartet was born out of the shared desire of Nicola Fazzini and Alessandro Fedrigo to create a sonic world, a scenario for new improvisational possibilities and innovative forms of musical writing. Interlaced sequences, pitch class sets, non-retrogradable rhythms, and polymeters are among the elements that constitute the grammar of the XY language, a fluid and original compositional tool, complex in structure but generous in its modes of communication.