The term 'DIRECTION TO VIOLINISTS' can be summarized by the four-letter word 'ARCO, ' which is an abbreviation for the Italian phrase 'ARCO e pizzicato, ' meaning 'bowed and plucked.' This term is used to describe the two main techniques of playing the violin, which are bowing and plucking the strings. Bowing is the most common technique used by violinists, while plucking is used to create a more percussive sound. The term 'ARCO' is used to remind violinists to use both techniques when playing the instrument.