CASALS ON INTONATION

‘Intonation,’ Casals told a student, ‘is a question of conscience. You hear when a note is false the same way you feel when you do something wrong in life. We must not continue to do the wrong thing.’ His assertion that ‘each note is like a link in a chain — important in itself and also as a connection between what has been and what will be’, applied as equally to intonation as to other aspects of interpretation. The notes of a composition do not exist in isolation; the movement of harmonic progressions, melodic contours and expressive colorations provides each interval with a specific sense of belonging and/or direction. Consequently, Casals stressed that the equal-tempered scale with its fixed and equidistant semitones — as found on the piano — is a compromise with which string players need not comply.* Playing in tune is therefore not a matter of adherence to intervals based upon a pre-ordained mathematical formula; it is a dynamic process, expressing the organic relationship between notes in a musical context, which Casals termed ‘expressive intonation’. The final judgement lies in the ever-sensitive ear of the musician.
 
*These remarks are also applicable to wind players and, not least, to singers.
 
Blum, David. Casals and the Art of Interpretation (pp. 140-141). University of California Press. Kindle Edition.

A deeper discussion of this can be found (and downloaded) here (see page 25).