The purpose of this study is to determine the influence of scholarly research on the orchestral performance practice of conductor Raymond Leppard.This study presents, with supporting evidence, what an international conductor does today to incorporate the results of research into the interpretation of music. From this study, the writer has presented the influence scholarly research has had on orchestral performance practice, how one of today's conductor and orchestras deal with the issues raised and how they are carried into current performances, and to what degree do musicologists influence his performance. Orchestra conductors continue to learn from performance practice research and young conductors must be encouraged to gain knowledge from this field.Three scholarly musicians, Arnold Dolmetsch (1858-1940), Edmund H. Fellowes (1870-1951), and Thurston Dart (1921-1971), among many others, did much to revive authentic performances of earlier music. Their critical and historical writings are based on original sources and the concept of interpretation by studying composers' original manuscripts and editions in order to better present their musical style and heritage. This developed a strong movement towards the study of incorporating authentic music research into music performance.Maestro Leppard is known particularly for his interpretations of seventeenth and eighteenth century music. He prepared the revivals of Monteverdi and Cavalli's Italian operas. Maestro Leppard has had many experiences with European and American orchestras and has made many recordings. The contents of the interview focused on (1) orchestra size and seating, (2) the authenticity of music, (3) some basic performance practice elements such as tempo, rhythm, dynamics, articulation and phrasing, ornamentation, vibrato, and portamento, (4) string bowing, (5) editions, and (6) interpretation and personal observations. / School of Music