[...] When suddenly provincialism finds its way into a tragic recital, it distorts the most beautiful poetry and offends the ear of the audience. Therefore it is of utmost importance that the actor in training frees himself from the mistakes of his dialect and pursues a complete and pure diction. [...]

J. W. GOETHE, 1803. Regeln für Schauspieler. [2004] Lexikon Goethe-Zitate:
Auslese für das 21. Jahrhundert aus Werk und Leben. München: Judicium Verlag GmbH

[...] Mozart - and here I'm only speaking about his Italian works - took his tempi from the natural flow of speech. If one does not understand the manifold meanings of the single words, there will inevitably be faster or slower tempi. [...] The tempo - by the way, this also applies to Verdi, who had the score of Don Giovanni on his piano for his entire life - is dictated by the language. [...]

RICCARDO MUTI in an interview with Walter Dobner, June 2001.
Program booklet of the Wiener Staatsoper for “Le nozze di Figaro”

[...] A profound knowledge of the language of the opera we sing is very important, not only for us to understand what we are singing, but especially because the music style has much to do with the characteristics of that specific language and by pronouncing the language correctly half of the musical problem is already solved. [...] Whoever does not know the language and therefore sings with a foreign accent does not sound "right" and the result will never be satisfying. [...] To get rid of an accent in singing is easier than when speaking. You have to work on each vowel, on each consonant, on each syllable and try to pronounce everything as perfectly as possible. This type of perfection, this singing "correctly" is an essential stylistic part of each opera. [...]

NICOLAI GEDDA in MATHEOPOULOS, H., 1988.
Bravo Berühmte Sänger über ihre großen Rollen. Munich: Kindler

[...] Theater translation (TT)1 is realized by way of surtitling, simultaneous interpreting, summarizing translation and other modes of translation. It does not appear as a research topic in the literature before Griesel (2000). Its object is to investigate different ways of interlingual transfer characterized by the fact that the boundaries between interpreting and translation are blurred. In contrast to drama translation, the production as a whole constitutes the ‘source text’. It has a multidimensional dimension in that translation modes are blurred and in that the target text may be presented in both written and/or oral form. [...]

GRIESEL Y. (2005). Surtitles and Translation - Towards an Integrative View of Theater Translation (Abstract). EU-High-Level Scientific Conference Series

[...] This article discusses the source text and reading situation of opera surtitles. It introduces opera from a multimodal viewpoint and differentiates between the dramatic text and the stage interpretation. With two versions of surtitles, it approaches two different surtitling strategies, the one that concentrates on the libretto and the other that focuses on the particular stage interpretation. As a result, the article asks if we should consider the stage interpretation to be the only appropriate source text of surtitles. [...]

VIRKKUNEN, R. (April 2004). The Source Text of Opera Surtitles. (Abstract) Montreal (CA): Meta - Translators' Journal

"The original is unfaithful to the translation."

Umberto Eco

"A different language is a different vision of life."

Federico Fellini

"The best thing on translation was said by Cervantes:
translation is the other side of a tapestry."

Leonardo Sciascia

"High thoughts must have high language."

Aristófanes

[...] In many translations there has neither been a poetic nor a music mind at work. They are simply carried out by people who know nothing about poetry or music [...] and therefore they translate the texts in the same way they would translate an article from the newspaper or a commercial text. . [...]

WAGNER, R. (1914). Oper und Drama, Sämtl. Schriften und Dichtungen.
Berlin: Deutsche Bibliothek Verlag

"Every disease is a musical problem; every cure is a musical solution."

NOVALIS in SACKS, O., 2007. Musicophilia - Tales of Music and the Brain. New York: Random House Inc

"All kinds of pain disappear and are cured by music, including everything that causes it."

Avicenna

"Who does not know music,
does not know anything that makes sense."

Seneca

"Almost all children respond to music. Music is an open-sesame, and if you can use it carefully and appropriately, you can reach into that child's potential for development."

Dr. Clive Robbins

[...] Dr. Sacks reports that patients with neurological disorders who cannot talk or move are often able to sing, and sometimes even dance, to music. Its advocates say music therapy also can help ease the trauma of grieving, lessen depression and provide an outlet for people who are otherwise withdrawn. [...]

St. Louis Post Dispatch sobre Dr. Oliver Sacks, "Awakenings"