I have recently been experimenting with a few other well known operas, apart from the three great ones of Mozart mentioned above, namely "The Marriage of Figaro", " Don Giovanni", and "Cosi fan Tutte". I had turned to Verdi's "Rigoletto" and "Aida" and Donizetti's "Lucia di Lammermoor". After listening to each of them a few times, I discovered that the Verdi operas were very disquieting and were of a tragic hue. The other opera of Donizetti, although also a tragic tale, had quite a pleasant and harmonic sound. The recording I had of it included Joan Sutherland and Luciano Pavarotti.
In the Verdi operas the tragedy was communicated transparently in the music; less so with the Donizetti. The Donizetti Opera ran for a little over two hours, but it was hard to detect during that time a musical arrangement that tore at ones senses as it does in the closing stages of both "Aida" and "Rigoletto". I left the Donizetti feeling elated and inspired by the music whereas I departed the other two considerably shaken by the music I had heard. The arias in the Donizetti are uplifting and inspiring where I found the Verdi complicated and secretive. Verdi had provided me with a tragic format for his operas, Donizetti had not. I now notice a slight feeling of apprehension and depression when listening to the Verdi, but I feel elated when listening to the Donizetti.
I should add that I have never seen any of these three operas performed on stage or watched DVD versions of them. All my observations of them are based on repeated listenings coupled with synopses of their plots. While I was listening to these operas, I could depend on excerpts of the stirring Bruckner symphony cycle to raise my spirits, but more of the excellent Bruckner another time.