At a SOLT Assembly, you are bound to hear sung at different times the hymn to Our Lady of the Most Holy Trinity. The words of the is hymn were written by SOLT Founder, Fr James Flanagan. The actual melody was written by Fr Rogel Rosalinas, SOLT, the current General Priest Servant.
Here is a recording from the 2006 General Chapter:
You can download the musical score here.
You can listen a most beautiful rendition, recorded by some young choral singers from Boston here.