or a composition:) music can be read as well as heard, and a piece of music written but never played is a piece of music notwithstanding. According to Edward E. Gordon the process of reading music, at least for trained musicians, involves a process, called "inner hearing" or "audiation", where the music is heard in the mind as if it were being played. This suggests that while sound is often considered a required aspect of music, it might not be. Jean Molino points out that "any element belonging to the total musical fact can be isolated, or taken as a strategic variable of musical production." Nattiez gives as examples Mauricio Kagel's Con Voce [with voice], where a masked trio silently mimes playing instruments. In this example sound, a common element, is excluded, while gesture, a less common element, is given primacy. However Nattiez goes on to say that despite special cases where sound is not immediately obvious (because it is heard in the mind): "sound is a minimal condition of the musical fact". Universal aspect There is disagreement about whether some aspects of music are universal, as well as whether the concept of music is universal. This debate often hinges on definitions. For instance, the fairly common assertion that "tonality" is a universal of all music may necessarily require an expansive definition of tonality. A pulse is sometimes taken as a universal, yet there exist solo vocal and instrumental genres with free and improvisational rhythm--no regular pulse--one example being the alap section of an Indian classical music performance. Harwood questions whether a "cross-cultural musical universal" may be found in the music or in the making of music, including performance, hearing, conception, and education. One aspect that is important to bear in mind when examining multi-cultural associations is that an English-language word (i.e. the word "music"), not a universal concept, is the object of scrutiny. For this reason it is important to approach apparently equivalent words in other languages with caution. Based on the many disparate definitions that can be found just in English language dictionaries,) it seems there is no agreement on what the word "music" means in English, let alone determining a potentially equivalent word from another culture. Kenneth Gourlay describes how, since different cultures include different elements in their definitions of music, dance, and related concepts, translation of the words for these activities may split or combine them,