A complete and clear exposition of the Catholic doctrine on the Blessed Sacrament, the work of Saint Thomas Aquinas, composed for the mass of Corpus Domini in 1264 (today Corpus Christi). The Gregorian melody is taken from a sequence dating from the 12th century. This is the first time in history, as far as we have records, that a performance of this piece is turned into an NFT. In addition, this NFT contains the only copy of the performance of the work. The file will be destroyed after mining, to make this NFT an absolutely unique piece.