Is it the basic sound? The technique? The musicianship? The sheer virtuosity? The perfect marriage of music and text? 

Greatest Voices of all Time Photos © Pavarotti: Decca/Terry O’Neill; Siepi: Decca; and supplied

Perhaps a combination of all these things, plus a heaping of that elusive ‘it’ factor that separates the merely good from the truly great? What is it about a particular singer that grabs us and never lets go, whose records become touchstones, interpretations blueprints?

Many of us will recall the very first time that we heard a singer who would become a cherished personal favourite. Or, maybe more rewarding still, finally grasped the artistry of a singer whose appeal had previously escaped us. But whether immediate
or gradual, a beloved voice becomes something very near to all-consuming, either for a short period in our lives or over the duration of a lifetime. The thrill of discovery is a heady one, presenting us with...