Answer: semiclassical

AnswerCrossword Clue
SEMICLASSICALLike Gershwin's orchestral works
semiclassical(of music) Having elements both of classical music and of other more popular genres
semiclassicalof, relating to, or being a musical composition that is intermediate in style between classical and popular music
semiclassical(of a theory or method) Intermediate between a classical or Newtonian description and one based on quantum mechanics or relativity