Early Music is a term used to describe pre-Classical Western music.
This means that Medieval, Renaissance, and Baroque music fall into this category.
Because Early Music is so old, virtually all of it (except that protected by a statutory perpetual copyright in one or more Berne Convention signatories) has fallen into the public domain.
... terms of the coefficients a, b and c, which are assumed to be real (but see below for generalizations) with a being non-zero. These solutions are also called the roots ...