Many years ago, I was invited to introduce a video of Mozart’s Die Zauberflöte in a culture centre and, when we we have finished listening to Sarastro’s O Isis und Osiris, a gentleman in the audience asked me “I’ve read that this aria is supposed to be an aural image of the sublime – and that wasn’t my impression”. I was at a loss there, for a) I had never promised him the “aural image of the sublime”; b) I couldn’t say that to him. He paid a ticket to be there! We were listening to Lászlo Polgár on the video from the Drottningholm Court Theatre, whom I have always found an elegant Mozartian. As I saw the laserdisc from the Met on a shelf, I said “we can always listen to Kurt Moll”. So I changed the disc, everybody was impressed with Moll’s voice and asked me if we could go further with the Levine performance instead. This is a non-story, nothing exciting happens here, but I always thought of this “aural image of the sublime”.
Sometimes I would listen to Kurt Moll to see if he gave me that impression. It is a exemplary Mozartian piece of singing, firm-toned, clear in diction, something we could say a “force of nature”. But I have to be honest – it never suggested me the aural image of the sublime. There is something too objective, the low notes are maybe too much “on your face” and maybe too dark – and I feel uncomfortable writing all those “too”, because Kurt Moll is the reference of how a bass should sing Mozart. For instance, no Osmin comes even close to him. Since that day in the culture centre, in the theatre or listening to a recording, I ask myself “have I heard the aural image of the sublime?”. At best, the answer is “almost”. There are tiny turn-offs that bring me back to earth when I listen to it – singers who slide down to their low notes, for instance. Lack of clean attack make is also a problem, but I feel for the bass singing this aria, because we can read his mind “every note must be perfectly pure” and most often than not there is very little legato there out of the sheer intent of producing an instrumental line. Also, because of the long lines, if there is some instability in the vocal production, it is going to be cruelly, mercilessly exposed. This is to basses what the Countess’s Porgi, amor is to sopranos. But nobody cares if the soprano is not really expressing the Countess’s depressive mood. Now in O Isis there must be some sort of fatherly, spiritual authority. And velvetiness and fulness of tone is essential. Even if everything else is going smoothly, if the voice is not rich, warm, dense and involving, then it just doesn’t work. Then there is something else, a game-changing feature very rare in this aria. Sarastro exerts a gentle authority (as we hear in his other aria) and a bass who can delve into his low notes gently, smoothly embodies this quality in musical terms. These low notes’ gentleness opposed to the violence in the high notes sung by the Queen of the Night are what this story is about.
That is why I was so impressed by Karl Ridderbusch’s account of that aria accidentally found on YouTube. As far as I know, there is no official recording of his Sarastro. This seems to be a TV show in Hungarian TV. There, Ridderbusch finally offered me the “aural image of the sublime”. It is a noble voice – my favorite König Heinrich in Lohengrin – whose purity of line does not involve any constriction of tone. The notes spin freely and firmly. In its highest reaches, their very vibration seems to exude spiritual force. He descends to his low register with naturalness, every note acquiring a natural and gentle darkness in the context of perfect legato. It is an immense performance – not ideally accompanied or recorded, unfortunately – and a great memento of a singer not always remembered as he should.
I HEAR VOICES 
Beautiful video.
I am probably the only person in the planet that thinks that Jose van Dam achieves this nobleness in Sarastro (Karajan recording). Every body else called him a terrible miscast.
Well, you’re not the only one: Karajan agreed with you. Van Dam is noble in tone and stylish in Mozart. Actually, Karajan chose Van Dam precisely for those reasons – he would have said that he didn’t want a… Biergarten Sarastro (or something like that, I don’t remember the words…). The problem is that Sarastro’s low notes are the role’s special feature. Hear how Mozart always unfurl them slowly, as if he was trying to wow the audience step by step. With Van Dam, it’s mostly tiptoeing. For a bass baritone, he does it beautifully. Probably better than all other bass baritones. But, yes, he sings it nobly and expressively. I agree.