The book Observations on Expressive Singing; or, Remarks on Ancient and Modern Singers, by Pier Francesco Tosi, is an important source of information for anyone interested in the art of singing. In his work, the author considers the technique of singing, expressive performance, and also gives advice on improving vocal skills. Tozi analyzes both ancient and modern singing, revealing the secrets of the mastery of legendary singers. This book will be a useful addition to the library of any musician or fan of vocal art.