The Mekhitarist Congregation of Venice preserves manuscripts categorized as “manrusumn” (“minute learning/science”) representing the very best of me­dieval Armenian neumatic notation for melismatic singing. The article at­tempts to present a comprehensive examination of the 18 Venetian manuscripts, ad­dres­sing issues related to their penmanship, neumation, and the symbolism of their marginal illustrations alongside the texts they represent. Issues related to the editing of these manuscripts, the nature and function of codices of “manr­u­sumn”, the earliest stratum of melismatic psalmody, forms of psalmody, few examples of Syriac and other eastern traditions are examined; as well as Father Ghevond Alishan’s substantive observations in the field of neumated “manru­sumn” codices.