Voice classification in non-classical music chart that follows. The ranges given below are approximations and are not meant to be too rigidly applied. Some men, in falsetto voice or as a result of certain rare physiological conditions, can sing in the same range as women. These do not fall into the female categories, instead called countertenors within classical music. Within contemporary music, however, the use of the term "tenor" for these male voices would be more appropriate. Teaching voice within non-classical music is an emerging field. Up to this point, voice teachers and voice research have been largely concentrated with classical methods of singing. However,
Terminology-oriented database relational database schema, or even an XML schema. Typically, terminology-oriented databases are not bound on a specific database type. Since the information content, which can be stored in object-oriented databases and in relational databases, is identical, data for a terminology-oriented database can be stored theoretically in any type of database as well as in an XML file. Thus, terminology-oriented databases may support several database systems for storing application data. Terminology Databases, when these contain Terms and Vocabularies, these become valuable for Ontologies and in turn ontologies can help process associated triples or complex predicates thus going deeper than hierarchies or