Tags: Genre, Music Genre, Topical Concept.
Old Style (O.S.) and New Style (N.S.) are sometimes used with dates to indicate either whether the start of the Julian year has been adjusted to start on 1 January (N.S.) even though documents written at the time use a different start of year (O.S.) or whether a date conforms to the Julian calendar (O.S.) formerly in use in many countries rather than the Gregorian (N.S.).The Gregorian calendar replaced the Julian in Catholic countries beginning in 1582.
