The letter refreshingly does not focus as some would on the opposition between order and charism, but rightly notes that there are hierarchical gifts as well as charismatic gifts, and they are meant to exist in ordered communion for the life of the Church.
One of the helpful paragraphs in the letter, and one that will strike a chord with many musicians, is in the section that explains how charisms are discerned. St. Paul said to test the spirits. What are the tests? According to the CDF, among them is this:
Acceptance of moments of trial in the discernment of charisms. Because a charismatic gift may imply “a certain element of genuine originality and of special initiative for the spiritual life of the Church” and in its surrounding “may appear troublesome”, it follows that one criteria of authenticity manifests itself as “humility in bearing with adversities”, such that: “The true relation between genuine charism, with its perspectives of newness, and interior suffering, carries with it an unvarying history of the connection between charism and cross”. Any tensions that may arise are a call to the practice of greater charity in view of the more profound ecclesial communion and unity that existsOne sees this kind of suffering most readily in the founders of religious communities, who almost as a matter of course endure all sorts of bewildering disappoints of the kind St. Raymond of Penyafort once mentioned:
The sword falls with double and treble force externally when, without cause being given, there breaks out from within the Church persecution in spiritual matters, where wounds are more serious, especially when inflicted by friends.The lives of the saints are chock full of these often surprising events and persecutions.
Church musicians of the reform-of-the-reform will readily recognize times when they felt that they or their friends appeared "troublesome" instead of eminently useful for the sake of the sacred liturgy. This is a painful experience for an artist, but one which should be endured faithfully and with humility.