Wolfgang Amadeus Mozart (1756-1791) was 26 and recently transplanted from Salzburg to Vienna when he began attending the weekly musical salons held by Baron Gottfried van Swieten in 1782. At the baron’s behest, Mozart began transcribing for strings fugues from Bach’s Well-Tempered Clavier, beginning his inculcation in the music of the Baroque master: homework assignments in advanced counterpoint.

By May of 1785, when the Fantasia in C minor, K. 475 was written, the influences of Bach and Bach’s son C.P.E. Bach were securely manifested in Mozart’s music. The sudden and stark contrasts of mood and color in the five sections of the Fantasia are modeled on the fantasias of the younger Bach, while the gripping narrative drive which pulls us from episode to episode is entirely the maturing composer’s dramatic gift. From the mysterious opening chords (like an invocation of the muse – a marshalling of inspiration) to the extended lyrical interludes and hectic outbursts, it is as though we are listening to a preserved improvisation. It is in the horizontal nature of the music, the contrapuntal juxtaposition of musical line accompanying musical line rather than a chordal accompaniment of a melody, that we hear the elder Bach’s legacy.

- Annotator Grant Hiroshima is the executive director of a private foundation and the former director of Information Technology for the Los Angeles Philharmonic Association.