Chart datum, level of water depth on a nautical chart. Datum or datum point, a (possibly arbitrary) reference baseline or point from which scientific measurements are made (from a Latin meaning of datum as a given, i.e. an accepted fact)
Music directors and composers must guide musicians and singers by preparing musical arrangements and helping them achieve the best possible sound. Musical talent. To become a music director or composer, one must have musical talent.
The term composer is often used to refer to composers of instrumental music, such as those found in classical, jazz or other forms of art and traditional music. In popular and folk music, the composer is usually called a songwriter, since the music generally takes the form of a song.