The purpose of the study was concerned with specific elements of the portion of the female voice commonly referred to as whistle or flute register. Three elements of vocal production were chosen for which past research has demonstrated relationships to source function. These elements included spectral characteristics, airflow rates, and perceptual identification. The research compared what the singer-subjects perceived as being whistle register phonations with that which they perceived as being head register phonations. A comparative technique was utilized where pitch, intensity and phonemic category were held relatively constant, register, therefore, being the only variable. Spectral characteristics and airflow rates of the two subject-determined registers were compared. In addition, an attempt was made to determine if the whistle register could be perceptually differentiated on the basis of voice quality,

This investigation traces the history and development of music theory in Mexico from the date of the first Mexican treatise available (1776) to the early second half of the nineteenth century (1866). This period of ninety years represents an era of special importance in the development of music theory in Mexico. It was during this time that the old modal system was finally abandoned in favor of the new tonal system and that Mexican authors began to pen music treatises which could be favorably compared with the imported European treatises which were the only authoritative source of instruction for serious musicians in Mexico.