Organology is mainly based on fieldwork, data collection and the following study and analysis of the gathered data. Key problems are the origin and development of folk music instruments, their structure, technology, description, classification, acoustic and musical analysis. Organology has an interdisciplinary structure. In the last years an increase of the concepts took place, by using challenging questionnaires, surveys, socio-cultural techniques, empirical and experimental methods, collecting and interpreting data in direct and indirect forms. To master these demands a series of formulas have been worked out in the Ethnomusicological Department in the 50s, which are used as to the present-day. They were permanently enlarged and supplemented in accordance with the new requirements and topics of the actual research. The formulas are presented in the paper.