John Sigismond Cousser - born Johann Sigismund Kusser in Pressburg, Hungary in 1660 - was a pioneering figure in the musical history of the Baroque era. Having worked professionally as a performer and composer across Europe over the span of a fifty-year career, this well-travelled and cosmopolitan musician was subsequently acknowledged by Johann Mattheson as having played a key role in the transmission of both the French and Italian musical styles throughout the German-speaking lands. Following study in Paris, Cousser was employed at a string of German courts, training musicians in the newly fashionable French style. At the court of Duke Anton Ulrich in Wolfenbuttel, he experienced at first hand performances of opera by Italian virtuosos and subsequently introduced countless German musicians and their audiences to the Italian musical style. Yet with the onset of war in 1701, Cousser was forced to seek his fortune elsewhere, moving to London in 1704 before settling permanently in Ireland. The Well-Travelled Musician expands current knowledge of Cousser's early life and professional career significantly, examining his particular role in the dissemination of music and musical styles throughout the German-speaking lands, as well as in early eighteenth-century London and Dublin. Drawing upon a rich body of primary sources, above all the unparalleled evidence contained in Cousser's so-called commonplace book, it reveals the practicalities of early modern musical exchange at a grass-roots level, from Pressburg (now Bratislava) to Paris, Hamburg to Dublin, and beyond.