This site provides high-quality PDF scores and recordings specifically based on the restorations found in the Graduale Novum . You can browse by liturgical season on the GradualeProject website
(A More Critical Edition according to Sacrosanctum Concilium 117). It is published in two volumes by ConBrio Verlagsgesellschaft Libreria Editrice Vaticana Volume I (Tomus I): Contains the chants for Sundays and Feasts ( De dominicis et festis Volume II (Tomus II): Covers the Proper of Saints and the Commons ( De feriis, propriis sanctorum et communibus Where to Find the Text and PDFs graduale novum pdf
Before 2011, the standard chant book in most Catholic parishes was the 1974 Graduale Romanum . That edition, while beautiful, was a compilation based on late medieval sources (primarily the 1908 Vatican Editio Vaticana ). The monks of Solesmes realized that the 1974 edition contained numerous inaccuracies, editorial compromises, and omitted many ancient melodic formulas. This site provides high-quality PDF scores and recordings
The editors re-examined the oldest adiastematic (without staff lines) manuscripts from the 10th century and diastematic (with staff lines) manuscripts from the 11th century to "correct" melodies found in the 1908 Vatican Edition. That edition, while beautiful, was a compilation based
That said, through the following channels: