squillo

Squillo is a technical term for the resonant, trumpet-like sound in the voices of opera singers. It is also commonly called "singer's formant", "ring", "ping", "core", and other terms. Squillo enables an essentially lyric tone to be heard over thick orchestrations, e.g. in late Verdi, Puccini and Strauss operas. Achieving a proper amount of squillo in any performing context is imperative: too much and the tone veers towards the shrill; too little and the purpose of the squillo cannot be achieved.