This volume of essays celebrates Hungarian musicologist László Somfai (b. 1934), head of the Budapest Bartók Archives for more than three decades, past president of the International Musicological Society, and a leading authority on the music of Joseph Haydn and Béla Bartók. His complex approach to source material involves evaluating biographical data while examining compositional sketches, notation, and performance practice, leading him to an "authentic" understanding of music that reaches beyond the discussion of musical sources. This honorary volume is devoted to the topics and approaches he has pioneered, without limiting the discussion to any particular period or style of music history. With a natural emphasis on the Viennese classics and Bartók, the 34 essays in this volume cover a range of music study, from the Middle Ages through the second half of the 20th century. Contributions from younger scholars and leading musicologists alike have been collected, including Somfai's former students, friends, and colleagues from all over the globe. Complete with an up-to-date bibliography of Somfai's publications, this book presents new and in-depth analyses of source studies and performance practices of many great composers and musical styles.