It can be done during Mass, during Vespers, or during the celebration of the word of God. There's music for the crowning and incensation, Magnificat antiphons, Litany of Loreto, and Introits, respectively.
There is no official "May Crowning" rite. The Order of Crowning an Image of the Blessed Virgin Mary has a misleading title as it is used only when a new and significant image is installed in a place of worship (as says the Springfield-in-Illinois letter above). In the end, I think Fr. David Friel's article on the Views from the Choir Loft blog is helpful:
At the school to which I am assigned, I used the thanksgiving and invocation prayer and the general intercessions from the Order of Crowning an Image of the Blessed Virgin Mary since the prayer of blessing from the Book of Blessings is not to my liking.
To participate in the discussions on Catholic church music, sign in or register as a forum member, The forum is a project of the Church Music Association of America.