[...] As is known to those involved in our church music, from the vast hymnological wealth of the Paraklitiki, only the services of Sundays are set to music in various Anastasimataria, and even these are not complete, as they lack those of the Little Vespers, the Triodion, the Cross-Resurrection, and those of the Theotokos; and from the services of the weekdays, only the penitential and martyrdom hymns sung during Great Lent and the funeral doxologies exist. Therefore, in the composition of this work, I attempted to present musically the entire necessary material from the Paraklitiki, taking into account not only its limited use in the parishes, but also its complete use in the monastic churches. [...]
(from the preface of Volume I)