Observations on the Present State of Music and Musicians: With General Rules for Studying Music, in a New, Easy, and Familiar Manner; in Order to Promote the Cultivation and Improvement of this Difficult Science. The Whole Illustrated with Many Useful and Entertaining Remarks, Intended for the Service of Its Practitioners in General. With the Characters of Some of the Most Eminent Masters of Music. To which is Added, a Scheme for Erecting and Supporting a Musical Academy in this Kingdom