Electronic synthesis of a castrato singing voice for a BBC4-TV programme

David M. Howard

The BBC wanted to have an electronic castrato voice for their BBC4-TV program: "Castrato", broadcast in July 2006. They were aware of what had been done for the film "Farinelli", and they were keen to have another approach adopted. The technique chosen was morphing of the voice of a boy with that of a man. Recordings were made of three cathedral boy choristers and two tenors singing "Ombra mai fu" (Handel). One tenor sang at pitch and one octave higher. This enabled a number of combinations to be attempted in terms of which boy was morphed with which tenor. One of the boys was the son of one of the tenors, enabling a "genetic" morph to be made. This paper will explore the technique and the process that lead to being able to provide an electronic version of the whole of the aria for performance with a live professional baroque orchestra on location in London. The filming was scheduled for one take only in order that the immediate response of the orchestral players could be recorded as part of the program. The final result was described as being somewhat "ghostly", but all agreed that it had human qualities but was definitely not the voice of a boy, girl, woman or man; a castrato?

David M. Howard
Audio Lab,
Intelligent Systems Research Group,
Dept of Electronics,
University of York, UK
dh@ohm.york.ac.uk