Lang was concerned above all with safeguarding the purity of musical knowledge as reflected in both scholarship and performance. Whether addressing his fellow musicologists or the general public, he expressed a broadly humanistic conception of musicology in his erudite and entertaining writings on such diverse subjects as Bach and Handel, the historical veracity of the film Amadeus, Marxist theory and music, and the controversial issue of "authenticity" in performance.
"Lang applies to issues of music and musicology in the second half of the twentieth century a sweeping outlook and genius for remarkably durable generalizations that characterize his earlier Music in Western Civilization. His eloquent plea for compromise in performing early music may upset some enthusiasts of 'authenticity' but is backed by solid good sense and a firm command of the historical context". -- Claude V. Palisca, Henry L. and Lucy G. Moses Professor Emeritus of Music, Yale University