The title is obviously alluding to speaking in tongues an expression from the bible that denotes a glossolalia or, also known as gibberish, a nonsensical speech. With regard to the expresssion of speaking in tongues, 'the Old Testament describes an ecstatic emotional state in which the adherents mind is absorbed into that of the deity, whom may be oblivious to the external world, while self-conscious and rationale thought may be impaired. (Edgerton, The 21st-Century Voice, p. 136)'. The subtitle, in contrary, has no double meaning, but points to those parts on which the slaps are executed. German composer Dieter Schnebel (1913-2018) from the Darmstadt generation and its protagonists, such as Pierre Boulez, John Cage, Mauricio Kagel, Karlheinz Stockhausen, etc., was very influential regarding new modalities and the directions he gave in composing for the voice. He created a number of vocal works, like Glossolalia or Maulwerke, all of which are questioning the voice in its common use as vehicle to communicate linguistic meaning. Instead Schnebel explores the sounding qualities of the voice by isolating specific muscle parts and let the performer focus on those, exclusively. The sounding results and the hereby transmitted range of human expressivity are astounding. For more insights on his work see Schnebel, 'Sprech- und Gesangsschule (Neue Vokalpraktiken)' [Speech and Singing School (New vocal practices)] my translation], in Mit Nachdruck: Texte der Darmstädter Ferienkurse für Neue Musik (2010), p.235- 249.