 His masterpiece, the "Great Canon" (also known as the "Canon of Repentance" or the "Great Canon of Repentance"), is the longest canon ever composed (250 strophes).It is written primarily in the first person, and goes chronologically through the entire Old and New Testaments drawing examples (both negative and positive) which it correlates to the need of the sinful soul for repentance and a humble return to God.It is divided into four parts (called "methymony") which are chanted at Great Compline on the first four nights of Great Lent (one part per night); later, it is chanted in its entirety at Matins on Thursday of the fifth week of Great Lent.