The work is part of a postgraduate course of study at the Sibelius Academy Department of Folk Music leading to the Doctor of Music degree in the Arts Study Programme. The largest part of the examination consisted of five concerts which were mainly performed on the 15-string kantele manufactured by Keijo Säteri (Leppävirta, Finland). This work represents an acoustical investigation of the specific 15-string kantele. The original model of this instrument is stored at the National Museum of Finland.
The first chapter addresses the basic principles of musical acoustics which are mainly examined from the perspective of plucked string instruments. The human auditory system and how musical sounds are interpreted by the brain are also considered.
In the second chapter, the results of the acoustical investigation of the 15-string kantele are introduced. The measurements were performed in an anechoic chamber in the Instrument Research Centre of the College of Craft and Design in Ikaalinen. Some strings of the kantele were played with different techniques and from different parts of the string. The recorded sounds were analysed by using the Intelligent Speech Analyser (ISA) program of Pitchsystems Oy, developed by Raimo Toivanen, Master of Science in Technology.
The acoustical behaviour of the kantele is very complicated and cannot be fully predicted beforehand. The harmonic structure of the sound of the instrument is not the same as the harmonic structure of the original sound from a single string. In addition to the construction of the wooden body, both the playing technique and the plucking point influence the harmonic structure. In contrast to the theory of string vibration when plucked in the middle, the second harmonic and other even harmonics clearly exist. This is one result of the non-linear behaviour of the kantele. The sympathetic vibrations of the free strings are particularly important in the sound production of this instrument. Partials which are not part of the harmonic series exist to a degree in every sample. The dual-mode vibration of the strings and the knotted termination at the other end give rise to the strong beat in the sound of the shorter strings but not in the sound of the longer strings.
The third chapter addresses the tuning issues. At first, four different general tuning systems are introduced and after that, the author's own way of tuning the 15-string kantele is explained. The higher pitch at the very beginning of plucking, the beating and the inharmoniousness of the kantele all affect the tuning. The focus is in attaining the type of overall timbre that pleases the musician and serves the music best at each moment the music is produced – and that varies from moment to moment according to circumstances and different situations.
