She was called “the voice of the century”. And with the opening notes of Aida’s “O patria mia”, heard full and clear through the crackle and needle-hiss of the 1923 recording, you realise why. Not only the voice itself, rich and seamless throughout the compass, but the life force pulsing through it. The soft, sustained high B flat of Leonora’s “Invan la pace”, from La forza del destino, thrills you to the marrow, as does the duet from the Nile scene of Aida, with Martinelli. Most of the disc is Verdi; some are alternative takes, one or two even better than the published versions. Volume 2 will presumably include the famous late-1920s recordings.