We previously discussed at length the difficulties of using young boys to sing the intricate and highly demanding music Bach wrote for the solo soprano voice, and I introduced you to an exceptional performer in recent history (Sebastian Hennig).

We very rarely – if ever – hear about star alto boys. Solo alto parts in Bach’s sacred music nowadays are, with a few extremely rare exceptions, always performed either by women or countertenors. Bach knew none of this. In German church music from the Baroque, as women were forbidden in organ lofts and castrati were reserved for the opera house, alto parts were always sung by boys (possibly the older ones on the cusp of adolescence). The now very common use of the solo countertenor voice is derived from the practice of English cathedral choirs where alto parts are generally sung by men using falsetto. (It’s interesting to note however that not all male alto singers use falsetto voice: some of them use their natural voice which is unusually high-pitched.) From a gender level, it seems only natural to ask countertenors to sing music originally intended for boys, but we have to remember this is an arrangement which was unknown to Bach.

The situation of boys singing alto parts is absolutely similar to the one we have discussed for boy sopranos: the technical level requested by Bach’s music is most of the time well beyond the capabilities of the young singers in our modern-day boys’ choirs.

The resurgence of the countertenor voice as a solo instrument in the past fifty years (following Alfred Deller’s pioneering efforts in the 60s) has offered an oft-welcome alternative with many top-notch singers from younger generations coming to the fore, some of them achieving an authentic star status. We have to remember however that using a countertenor to sing an alto part in Bach is as far from the composer’s intentions as using a woman for a soprano part. And yet this is often among the best options available to us now, if only for matters of pitch: at baroque pitch on period instruments (A = 415 Hz), alto parts are sometimes a little too low for regular mezzos.

In my experience, it all depends on the quality of the singer, and I have heard as many mezzos as countertenors (or any other vocal type for that matter) struggling with the extreme demands of Bach’s writing. Some people have a hard time hearing a man singing a text infused with maternal overtones (as in some arias from the Christmas Oratorio for instance) and will as a rule prefer to hear a mezzo or contralto over a countertenor in this specific repertoire. It is a fair point, but we have to remember that both options are incorrect historically, and that Bach wrote this very maternal music for a young boy… Beyond that, it is purely a matter of preference.

What is certain however is that Bach must have met with a few exceptional young alto singers at specific periods in time, though unfortunately history hasn’t retained their names. In 1726 for instance, he wrote three cantatas (BWV 35, 169 and 170) entirely devoted to the solo alto voice (except for a final harmonized chorale in BWV 169). All three are works of a fully mature Bach summoning the skills of an exceptional performer.

I have chosen for you the opening aria from cantata BWV 170, which has become an absolute favorite of mezzos, contraltos and countertenors alike. The only reason cantata BWV 170 is not performed as often as the other great solo cantata by Bach (Ich habe genug BWV 82) is because it requests a double-manual organ for the third movement, an instrument rarely found in concert halls.

The text of this cantata for the sixth Sunday after Trinity (which fell on July 28 in 1726 – exactly twenty-four years before the composer’s death), by the Darmstadt die-hard pietist poet Georg Christian Lehms, is all about combatting sin and lust in order to access salvation of the human soul:

Contented peace, beloved delight of the soul,

You cannot be found among the sins of hell,

But only where there is heavenly harmony;

You alone strengthen the weak breast.

For this reason, nothing but the gift of virtue

Should have any place in my heart.

The ideas of “contented peace” and “heavenly harmony” set the mood for this beautiful pastoral lullaby reminiscent of the aria Mache dich, mein Herze rein from the St. Matthew Passion: a lulling 12/8 motion suffused with languorous repeated notes played with bow vibrato by the strings and continuo, topped with a luminous first-violin line doubled by an oboe d’amore for more rustic charm. The tone is almost operatic here and reminds us, albeit with very different musical means, of the idyllic atmosphere created by Handel in some of his most famous pastoral arias, notably Verdi prati (Alcina) and Ombra mai fu (Serse).