A PEDAGOGICAL UTILISATION OF THE ACCORDION TO STUDY THE VIBRATION BEHAVIOUR OF FREE REEDS PACS REFERENCE: 4310.Sv Llanos-Vázquez, R.1; Elejalde-García, M.J.1; Macho-Stadler, E.1; Alonso-Moral, J.2 1Dpto. Física Aplicada 1. Escuela Superior de Ingenieros. UPV/EHU. Address: Alameda de Urquijo s.n., 48013 Bilbao, Spain. Tel: 34-946014256. Fax: 34-946014178. E-mail:
[email protected] 2Conservatorio Superior de Música Juan Crisóstomo de Arriaga Address: General Concha 20, 48010 Bilbao, Spain. Tel: 34-944412136. Fax: 34-946014178. E-mail:
[email protected] ABSTRACT This paper is concerned primarily with an educational approach to the accordion sound generation mechanisms. Accordions are made to sound by buzzing a thin steel tongue, which is attached to one side of a metal plate containing an aperture through which the reed tongue can actually pass. The accordion utilises the free reed principle, is hand-held and is powered by bellows. The aim of this work is to present the pedagogical steps that focus on the knowledge of free reed behaviour and the pressure forces that excite the reed vibration. INTRODUCTION The term Accordion is the proper generic term for all members of a complex family of free-reed aerophones. The accordion consists of a series of air-actuated free reeds tuned to notes of a musical scale and controlled by means of a keyboard. The family is divided into two preliminary halves: “Diatonic” accordions, that play different pitches when bellows are expanded or compressed and “Chromatic” accordions, that sound the same pitch in both bellows directions.