Three brilliant arias for alto
In my opinion, there are three arias which are very helpful to start working the vocal technique in Alto voices: Verdi prati, selve amene (opera: Alcina, role: Ruggiero, Handel), Buss und Reu (Oratorio: St Matthew Passion, Bach) and Qui sedes (Oratorio: Gloria, RV 589). All of them invite a singer to develop legatto singing which is essential to vocal accuracy and good intonation. According to Miller legatto singing means to go fluid over the melody “binding one sound to the next”. In fact “There is a strong conviction among vocal cognoscente that excellence in the singing can exist only if the art of legato has been mastered” (Miller, R. (1996) On the Art of Singing, Oxford University Press).
These three arias are also all written for a middle range Alto voice. This is another very important aspect to start developing any voice before working in a high or low range. That is the best way to find a proper balance between chest and head voice. For instance in Verdi Prati (range: C/Do#3-E/Mi4) notes are written most of the time in the middle range. On the other hand, the melody runs through small intervals between notes, another very helpful aspect for a beginner singer. Melody in Buss und Reu also develops itself with the same features. However, we still often find downward phrases, which are very useful to connect the head voice with chest voice as well.
At the same time, all of them are written in different languages. Verdi Prati is in italian, which for many singing teachers and pedagogues is the proper language for singing learning. This idea has to do with the fact that all vowels are clear, not nasal, enabling a good intonation in the singing mechanism, as well as the articulation of a greater amount of vowels in the front of the mouth. Therefore, starting singing in Italian enables the singer to find a good balance among articulators, which helps also to eliminate tension in the vocal tract. The aria Qui sedes is written in latin, which has the same linguistic root as italian, sharing with it many similarities and having almost the same technical advantages. On the other hand, this aria also invites singing students to work the text articulation very precisely, once all music develops itself over a very small phrase: Qui sedes ad dexteram patris, miserere nobis. That becomes very helpful for a beginner who just needs to adapt the articulation principles in this small text to all the musical passages. Buss und reu is written in german, which is a language not so helpful for intonation as the previous ones. However, in this aria the predominance of rounded vowels as [u], [o] helps the singer to get a good vocal aggiustamento.
Finally, the last technical aspect that I believe a singer can develop is coloratura in the aria Qui sedes. This aria provides small coloratura phrases, which is the capacity to sing fast notes in just one syllable (runs, trills…). That becomes a good way to begin working coloratura in a singer without experience in ornamentation singing. In this aria these fast notes appear slowly into several melodies, where the singer can set them after a few bars of long notes.
These are for me the most evident aspects which these three arias can provide in the development of an Alto voice. However, it is also important, at the same time, to combine a great breathing technique and the expressivity through the meaning and the context of the text, which is essential to develop all voices from the beginning.