I've had the pleasure of playing and coaching "In questa reggia" from Puccini's Turandot many times in the last few years. Among the recordings I've heard and seen, this one stands out - the legendary Eva Turner, not just for her vocal power and beauty of tone, but for the surprisingly high quality of audio for the time:
Click here for another remastering of the same recording, with a slightly different sound.
James Brown and Luciano Pavarotti
Two Videos of Pavarotti singing Nessun Dorma
Keith Klassen Sings Di miei bollenti spiriti