Pope John Paul II advises support for the bishops to make good discernments in the efforts of promoting sacred music:
13. Lastly, I would like to recall what St Pius X disposed at the practical level so as to encourage the effective application of the instructions set out in his Motu Proprio. Addressing the Bishops, he prescribed that they institute in their Dioceses “a special Commission of qualified persons competent in sacred music”[TlS 24]. Wherever the papal disposition was put into practice, it has yielded abundant fruit. At the present time there are numerous national, diocesan and interdiocesan commissions which make a precious contribution to preparing local repertoires, seeking to practise a discernment that takes into account the quality of the texts and music. I hope that the Bishops will continue to support the commitment of these commissions and encourage their effectiveness in the pastoral context[Vicesimus Quintus Annus 20].
Not every diocese has an active committee, but many that do find the ministry quite fruitful. I don’t know that repertoire is always on the top of the list of tasks. There is much formation to be done. I’m a believer that personnel is worth more investment than the particulars. Neither excludes the other, of course. But forming good parishmusicians lays the groundwork for a finer repertoire.
Note the importance given to liturgical texts, presumably originals or adapted, not propers.
The CDWDS is given a mandate:
In the light of the experience gained in recent years, the better to assure the fulfilment of the important task of regulating and promoting the sacred Liturgy, I ask the Congregation for Divine Worship and the Discipline of the Sacraments to increase its attention, in accordance with its institutional aims[Pastor Bonus 65], in the sector of sacred liturgical music, availing itself of the competencies of the various commissions and institutions specialized in this field as well as of the contribution of the Pontifical Institute of Sacred Music. Indeed, it is important that the musical compositions used for liturgical celebrations correspond to the criteria appropriately set down by St Pius X and wisely developed by both the Second Vatican Council and the subsequent Magisterium of the Church. In this perspective, I am confident that the Bishops’ Conferences will carefully examine texts destined for liturgical chant[Dies Domini 50, Liturgiam Authenticam 108] and will devote special attention to evaluating and encouraging melodies that are truly suited to sacred use[GIRM 393].
This task has been something of a lost cause, hasn’t it?