1. a person in charge of the musical components of a theatrical production, with duties such as selecting cast members, leading music rehearsals with the performers, and conducting the cast and pit orchestra during the show.

2. a superhuman.
The music director is the most underrated person working in an award show. Ever wonder how the orchestra knows just when to play a recipient off during a lengthy speech, or what piece to perform to cleverly introduce a presenter? That is all the work of a music director.
by chiefyblues July 28, 2022
A director hired mainly for his vision and ability to place and execute stunning visual images, stories and actions into the short time frame of a song. Usually considered as short films lead by musical tracks rather than dialogue.
Hype Williams, X, Director Hugo V, Spike Jonez are a few examples of some of the most notable music video directors.
by V Freightrain August 1, 2009