The publication Catalogus fragmentorum cum notis musicis medii aevi e civitate Trenchini updated knowledge of interdisciplinary researches on the oldest sources of musical culture in the territory of Slovakia. The monograph is the sixth volume of the Catalogus fragmentorum cum notis musicis medii aevi in Slovacia edition, published by the Institute of Musicology of the Slovak Academy of Sciences since 2008. The work is in English language. It treats the medieval fragments from the State Archive of Trenčín – preserved as upper bindings of municipal protocols. The publication contains a detailed analysis and evaluation of precious liturgical manuscripts from the 14th century up to the beginning of the 16th century (11 antiphonaries, 8 graduals, 1 breviary, and 1 missal). The sources are processed as complex interdisciplinary studies (historical assumptions, codicological-palaeographical analysis, musical-palaeographical analysis, musical-liturgical analysis) integrated by a catalogue of manuscripts in Latin language. All preserved materials witness the musical heritage of liturgical chant – cantus planus.