The term ‘algorithm’ is roughly defi ned as a set of rules for solving a problem in a fi nite number of steps. Algorithms in music are used in a variety of ways, including sound synthesis and composing, whenever result benefi ts from applying a series of rules or instructions. Paweł Szymański has composed many such works and one of them is Singletrack for piano solo. Basing on analysis the author concludes that Singletrack’s algorithm is as following: 1. Create four motifs 7-, 9-, 11-, and 13-notes long with the same beginnings and endings if possible. 2. Build a single-voice construction taking in turn only one sound from the shortest to the longest motifs. After exhaustion of all sounds of any motif take sounds from the beginning of the motif and continue. 3. Do not change a register of the individual sounds. 4. See if a construction is possible to play by a pianist. 5. Continue to build the single-voice construction till desirable length. The algorithm above had resulted in initial structure, which Szymański changed later in many ways according to aesthetic rules. It is just the fi nal structure that shows the master class of the composer. However, the author puts off discussion of it on the other occasion.