Acting as an instrument; serving as a means; contributing to promote; conductive; helpful; serviceable; as, he was instrumental in conducting the business.
Pertaining to, made by, or prepared for, an instrument, esp. a musical instrument; as, instrumental music, distinguished from vocal music.
Applied to a case expressing means or agency; as, the instrumental case. This is found in Sanskrit as a separate case, but in Greek it was merged into the dative, and in Latin into the ablative. In Old English it was a separate case, but has disappeared, leaving only a few anomalous forms.
I realised a long time ago that instrumental music speaks a lot more clearly than English, Spanish, Yiddish, Swahili, any other language. Pure melody goes outside time. Carlos Santana
I've had a life that has taken many interesting paths. I've learned a lot from mentors who were instrumental in shaping me, and I want to share what I've learned. Herbie Hancock
I grew up in Ohio, where civil-rights accomplishments had already begun to accelerate before Martin Luther King appeared. In hindsight, we know that many people, black and white, were instrumental in changing the Jim Crow status quo on all levels. Rita Dove
I had my first 'Survivor Series' in 1991 and I was fortunate enough to be an instrumental part of the shows I was on. Ric Flair
America owes most of its social prejudices to the exaggerated religious opinions of the different sects which were so instrumental in establishing the colonies. James F. Cooper