Among the European countries, Hungary had the richest corpus of plainchant in vernacular in the 17th century. The complete liturgy was put down with a musical notation for the first time in Gál Huszár’s songbook (1574). The Eperjes Gradual (1635) acquired a special position among the Protestant graduals in Hungarian by being the only Lutheran gradual and the only one containing polyphonic pieces. A comparison of the Magne Deus-melody in both sources concludes that the differences of the two monophonic melodies can be interpreted as reminiscences of an organum-like polyphonic practice. This hypothesis is sustained by a series of examples including not only melodies of Gregorian origin but also Hungarian-texted monophonic hymns from the 16th to the 18th centuries.