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.
As a singer, your voice is your instrument. If you want to become a virtuoso, you have to practice, practice, practice. Whether it's singing in the shower, in the car, for your grandparents, in a church choir, or in your room alone, practice. Practice singing your favorite songs, but also ones in different styles.