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.
Architects need to be familiar with a wide range of technologies, methodologies, understand the software lifecycle, have design experience, and some say an architect must write code, and so on and so forth. Indeed, the hard skills are important, very important. However it doesn't stop there.