''Squillo'' is the resonant, trumpet-like sound in the voices of opera singers. It is also commonly called "singer's

formant In speech science and phonetics, a formant is the broad spectral maximum that results from an acoustic resonance of the human vocal tract. In acoustics, a formant is usually defined as a broad peak, or local maximum, in the spectrum. For harmoni ...

", "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. ''Squillo'' is recognizable by a distinctive brilliant, ringing quality in the timbre of the voice. This perception is caused by the presence of a peak in the 2 - 5 kHz frequency range, to which the human ear is particularly sensitive. The amplification of these particular harmonics is believed to be a result of a narrowing of the

Aryepiglottic fold The aryepiglottic folds are triangular folds of mucous membrane of the larynx. They enclose ligamentous and muscular fibres. They extend from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name 'aryepiglottic'. They ...

just above the larynx. Voices with naturally acquired ''squillo'', i.e. having naturally strong higher formants, are especially prized in opera because they allow a singer to sustain lyric qualities such as limpid high notes, and consistency of tone throughout the vocal range, even in dramatic singing. Voices with ''squillo'' are also easier to record. Uses of the ''squillo'' include: * projecting a small timbre e.g.

Tito Schipa Tito Schipa (; born Raffaele Attilio Amedeo Schipa; 2 January 1889 in Lecce16 December 1965) was an Italian lyric tenor, considered the greatest tenore di grazia and one of the most popular tenors of the century. Biography Schipa was born as ...

, Bidu Sayao * underscoring a dramatically important passage e.g. ''No, non voglio morir'' in ''Sola, perduta abbandonata'' from Puccini's Manon Lescaut * singing through a thickly textured orchestration, e.g. the final bars of ''Libera me'' from

Verdi's Requiem The ''Messa da Requiem'' is a musical setting of the Catholic funeral mass (Requiem) for four soloists, double choir and orchestra by Giuseppe Verdi. It was composed in memory of Alessandro Manzoni, whom Verdi admired. The first performance, at th ...

, in which a soprano has to compete against a ''tutti'' orchestra and full chorus * supporting a pianissimo note floated over an orchestra (which also demands a secure breath control) e.g.

Montserrat Caballé Montserrat Caballé i Folch or Folc (full name: María de Montserrat Bibiana Concepción Caballé i Folch (, , ; (12 April 1933 – 6 October 2018), known simply as Montserrat Caballé, was a Catalan Spanish operatic soprano. She sang a wide v ...

Renata Tebaldi Renata Tebaldi ( , ; 1 February 1922 – 19 December 2004) was an Italian lirico-spinto soprano popular in the post- war period, and especially prominent as one of the stars of La Scala, San Carlo and, especially, the Metropolitan Opera. ...

* supporting a long trill e.g. Joan Sutherland * simulating a scream without compromising the timbre, especially in a verismic opera (albeit that a

bona fide In human interactions, good faith ( la, bona fides) is a sincere intention to be fair, open, and honest, regardless of the outcome of the interaction. Some Latin phrases have lost their literal meaning over centuries, but that is not the case ...

scream is sometimes used in opera, e.g. Tosca's jump to death in

Tosca ''Tosca'' is an opera in three acts by Giacomo Puccini to an Italian libretto by Luigi Illica and Giuseppe Giacosa. It premiered at the Teatro Costanzi in Rome on 14 January 1900. The work, based on Victorien Sardou's 1887 French-language dramati ...

) * giving an impression of 'youth' to an aged voice, mainly via a cultivation of the head register (cf. Section IX ''Meine Gesangskunst'', by

Lilli Lehmann Lilli Lehmann, born Elisabeth Maria Lehmann, later Elisabeth Maria Lehmann-Kalisch (24 November 1848 – 17 May 1929) was a German operatic soprano. She was also a voice teacher. Biography The future opera star's father, Karl-August Lehmann, wa ...

; exemplified vocally by

Mirella Freni Mirella Freni, OMRI (, born Mirella Fregni, 27 February 1935 – 9 February 2020) was an Italian operatic soprano who had a career of 50 years and appeared at major international opera houses. She received international attention at the Gl ...

) Singers known for their mastery of this technique have included

Maria Callas Maria Callas . (born Sophie Cecilia Kalos; December 2, 1923 – September 16, 1977) was an American-born Greek soprano who was one of the most renowned and influential opera singers of the 20th century. Many critics praised her ''bel cant ...

Kirsten Flagstad Kirsten Malfrid Flagstad (12 July 1895 – 7 December 1962) was a Norwegian opera singer, who was the outstanding Wagnerian soprano of her era. Her triumphant debut in New York on 2 February 1935 is one of the legends of opera. Giulio Gatti-Casa ...

, Giuseppe di Stefano,

Jussi Björling Johan Jonatan "Jussi" Björling ( , ; 5 February 19119 September 1960) was a Swedish tenor. One of the leading operatic singers of the 20th century, Björling appeared for many years at the Metropolitan Opera in New York City and less frequen ...

and

Luciano Pavarotti Luciano Pavarotti (, , ; 12 October 19356 September 2007) was an Italian operatic tenor who during the late part of his career crossed over into popular music, eventually becoming one of the most acclaimed tenors of all time. He made numero ...

. Some dramatic singers may also employ ''squillo'' rather than volume in the course of a performance, for example

Birgit Nilsson Märta Birgit Nilsson (17 May 1918 – 25 December 2005) was a celebrated Swedish dramatic soprano. Although she sang a wide répertoire of operatic and vocal works, Nilsson was best known for her performances in the operas of Richard Wagner a ...

References

{{opera terms Singing techniques Italian opera terminology