Nadia Boulanger on music and genius. Is it appropriate to use genius to describe a person?

Nadia Boulanger, a famous teacher who inspired many great composers including Stravinsky, Elliott Carter and Philip Glass, also the sister of Lily Boulanger, talked about music and genius on the aspect of pedagogy. After watching the interview, my idea of genius is a person with obsessive love with music who would do anything for it and can not live without it. Hmm...it is not easy and rare to become a genius, indeed.