Born in Cologne, Schmidt studied musicology, Germanistic, history of art and philosophy in the universities of Bonn, Berlin and Vienna.
Schmidt was a research assistant at the Arnold Schönberg-Institute of the University of Music and Performing Arts Vienna, the German Academic Exchange Service, and the Österreichische Forschungsgemeinschaft [de] scholarships in Austria, Italy and several times in the USA.
Schmidt has spent many years of teaching (as lecturer, substitute and visiting professor) at universities in Austria, Switzerland, Germany and the Netherlands in addition to his academic duties as music journalist, exhibition curator and concert dramaturg.
Schmidt's work focuses on the history and aesthetics of music of the 18th to 20th centuries (books on Wolfgang Amadeus Mozart, Johannes Brahms, Arnold Schönberg and Ernst Krenek, among others).
Schmidt is also particularly interested in persons and phenomena that lie beyond canonized historiography: for example, he has worked together with students on exhibitions and publications on the composers Felix Weingartner and Yevgeny Gunst as well as on the Swiss origins of the national anthem of Lesotho.