I would say especially the live recordings, because we can appreciate her true sound, without reverberation or filters or electronic amplification. In my selection, a 26-year-old Callas tackles one of Verdi’s most challenging soprano arias with apparent ease. I cannot imagine having been able to achieve this at such a young age.

When I prepared Nabucco for my concertante debut in 2023, part of my learning process was to listen to recordings by great singers. Early Callas was an inspiration. She understood that Verdi wrote a bel canto role; singing it muscularly, spinto, has proven to ruin voices that cannot handle that misguided approach. The demands of this aria (not to mention the role of Abigaille) – which includes both dramatic and lyric singing, two octave leaps, pianissimi and more – are not for the faint of heart… or voice.