A composer (Latin com+ponere, literally "one who puts together") is a person who creates music, either by musical notation or oral tradition, for interpretation and performance, or through direct manipulation of sonic material through electronic media. The level of distinction between composers and other musicians varies, which affects issues such as copyright and the deference given to individual interpretations of a particular piece of music.^{[citation needed]} In the development of European music, the function of composing music initially did not have much greater importance than that of performing it.^{[citation needed]} The preservation of individual compositions did not receive enormous attention and musicians generally had no qualms about modifying compositions for performance. Over time, however, the written notation of the composer came to be treated as strict instructions from which performers should not deviate without good practical or artistic reason. Performers do, however, play the music and interpret it in a way that is all their own. In fact, in the concerto form, the soloist would often compose and perform a cadenza as a way to express their individual interpretation of the piece.