Mozart, 6 Sonatas For Violin And Piano KV 55-60 (Breitkopf & Härtel)

Mozart's "Romantic Sonatas" is a collection of 6 sonatas for violin and piano, but their authorship is not fully authenticated. The original autographs are missing, and the publisher who printed them, Breitkopf & Härtel, had doubts about their authenticity. Konstanze, Mozart's wife, offered the sonatas to the publisher in 1799, but they expressed disappointment and asked for the original manuscript to verify their authenticity. However, the original manuscript could not be found, which only increased Konstanze's doubts about the sonatas' authenticity. It's possible that she had even learned or discovered the composer's name by then.

On November 16, 1800, she wrote to others stating that she had left Breitkopf & Härtel to judge the music pieces again and estimate them based on their own criteria. She also stated that she had completely given up any guarantee that the music pieces were composed by Mozart. This was a significant decision for her.