Instrumental
An instrumental is a musical composition or recording without lyrics, or singing, although it might include some inarticulate vocals, such as shouted backup vocals in a Big Band setting. The word "song" is widely misused by people in the popular music industry to describe any musical composition, whether sung or played only by instruments."The music is primarily or exclusively produced by musical instruments. An instrumental can exist in music notation, after it is written by a composer; in the mind of the composer (especially in cases where the composer himself will perform the piece, as in the case of a blues solo guitarist or a folk music fiddle player); as a piece that is performed live by a single instrumentalist or a musical ensemble, which could range in size from a duo or trio to a large Big Band, concert band or orchestra.
Economics
Economics is a subject that really relates to core aspects of human well-being, and there’s a methodology for thinking about these things. This was a very appealing combination to me. Market systems are capable of massive breakdowns that can result in long, devastating periods of high unemployment. And I felt that economists had really learned something about how to address that.
Janet Yellen, in "The Hand on the Lever" in The New Yorker (July 21, 2014) by Nicholas Lemann