Martin y Coll was primarily an organist, and then probably secondly a theorist -- a pair of treatises dating from 1714 and 1734 respectively were likely the prize achievements of his life, even if today it is his skill as an archivist and compiler that endears him to musicologists. The four volumes of Flores de Música contain several hundred keyboard pieces, nearly all of which are anonymous. (Martin y Coll assumed that readers of his anthology would recognize the pieces immediately, and, as the pieces were probably rather famous ones at the time, he was most likely correct in the assumption). The authors of many of the pieces have been identified by modern scholars, however, and the list of composers included reads like a who's-who of music in Martin y Coll's day -- Corelli, Handel, Frescobaldi, Cabanilles, and Cabezón.
Martin y Coll issued a fifth volume of keyboard music (mostly for organ) at some point, called Ramillete oloroso: suabes flores de música para órgano -- and these 250-or-so pieces are definitely his own compositions.