The human voice is capable of producing some amazing sounds. A number
of delicate organs in the mouth and throat can be
taught to modify the color, tone, and timbre of a person's voice and
provide quality and variety unmatched by even the grandest piano. I
will dedicate the next couple of posts to exploring the outer reaches
of what the human voice is capable of.

To find the lowest extreme, we must look to Mozart. The aria "O,
wie will ich triumphieren" in the opera "Abduction at the Seraglio"
contains the lowest note in the classical repertoire - D2 (see above). What could
have compelled Mozart to write such a low note? True, he was writing
for a bass singer with an extraordinary range. Still, the music itself
needed to have the artistic integrity to reasonably incorporate such a
bizarre element.. Mozart couldn't just stick a very low note in the
aria, and he knew it. It's no good to create weird music for the sake
of being different or weird. The low note must carry a meaning aside
from its peculiarity. So, Mozart made it part of a musical theme in the
aria. This 7- note theme goes with the words "denn nun hab ich vor euch
Ruh." The theme is quite simple, merely 5 notes descending in whole
steps from A3 followed by 2 notes re-ascending, also in whole steps.
See?

But this simple, benign theme actually sets up a witty and delightfully cruel joke, which, for a genius like Mozart, is easy to see but for us is quite surprising. After a brief pause, the theme is repeated, only the first note is an
entire octave lower than before - at A2. As before, the theme descends
5 notes to D2. Again, this famous note D2 is the lowest sung note in the
classical repertoire.
Reaching it is no easy feat. Perhaps showing uncharacteristic mercy,
Mozart allows his theme to jump to a
more comfortable A2 before having the bass sustain the long note.
Despite having to reach D2, this was the easy part.

The theme pops up again at the end of the aria. This time, it follows a
difficult coloratura section in which the bass must sing an elaborate
tune full of runs up and down on the musical scale. As you can see
below, right before beginning the "denn nun..." theme, the bass is
required to go from E2 up to A3 and then back down to A2 in one step.
That bit is tiresome, but Mozart affords the bass only the tiniest rest
before beginning the "denn nun" theme.

The familiar 5-note cascade begins again - this time on D3 (see above). Uh-oh. If
on the first go-around, we descended an entire octave for the repeat,
does this mean that this time, the repeat will begin at D2? That's what
the rules tell us, but Mozart is making up the rules and he does
something way more ingenius.
The repeat begins not an octave lower, but at the same spot. Barring a
couple of minor semi-tone changes, the repeat is exactly the same as
the first run. This means that, according to the rules, this theme will
end relatively easily for the bass. On the ascent in the second repeat,
he'll jump up to a very comfortable D3 before having to sustain the
long note.

But no! Instead, Mozart makes him go DOWN - down FOUR steps to D2. The
bass is now faced with the sickening challenge of holding a D2 note for
8 bars.

I've heard many basses try to do this aria. Only one I've heard has
done it convincingly. He's not the one in this video, but unfortunately this is the only one I have on video. Time cues are in the text to the side.