Vincenzo Bellini was the least prolific of the bel canto composers, having produced only ten operas compared to Rossini's thirty-nine and Donizetti's sixty-six. But he was generally considered the most sensitive of the three composers, particularly with regard to his approach to the poetry presented to him by his librettists. La sonnambula" and Norma are considered his most important works, but his operas I Puritani and Il pirata are major works of the bel canto period as well.
The elements of the bel canto style include: 1) the emphasis of the voice or the vocal line over the orchestra; 2) the sparing but elegant use of the orchestra as accompaniment to the voice; 3) sensitivity to text; 4) 'pictorial' writing for the voice in order to comment upon or 'paint' the text; 5) long vocal phrases, and 6) the use of the traditional Italian operatic structures — the scena, the double aria, (cavatina and cabaletta), concertato finales and two-movement duets (all of which are elements of opera that had been established once and for all by Rossini in his serious operas). All of these elements can be found in the opera Norma.
If one listens to Norma's Act I aria Casta diva (Chaste goddess), many of these style elements will be clearly heard. The orchestral accompaniment is as simple as possible with the violins outlining chords and the lower strings providing pizzicato notes on strong beats. If you think about it, this is a kind of harp-like accompaniment allowing the voice to 'float' freely and easily above. Every word can be clearly heard because of the composer's restraint in using the orchestra; therefore Bellini shows great sensitivity to the text which is essentially a hymn to the moon goddess. In terms of that ritual, hymn-like style, the tempo is slow, the orchestration is simple and the 'atmosphere' created is one of holiness, of a person reciting sacred words on behalf of the people. Compare this work to the "Laudate Dominum" from Mozart's Vesperae Solennes de Confessore, a work for soprano, chorus and orchestra from one of the master's liturgical or church works. The sonic environment that Mozart creates is quite similar to Bellini's aria for Norma.)
The composer also shows sensitivity to the text by 'painting' it. Certain words get special treatment. The first instance of this sensitivity occurs with the first two words of the aria, Casta diva (Chaste goddess). Each word is engulfed by melodic turns of phrase or ornaments underlining Norma's prayer to the goddess. The fact that these two words encompass one vocal phrase also tells us of the importance of the deity being addressed: Casta— breath — diva — breath would diminish the character of the phrase "chaste goddess". Caaaaaaa-sta diiiiiiii-va — breath — gives the words heft and importance. Notice, too, how the pitch of the voice rises as we come to the climactic phrase at the end of the first verse of the text: senza nube e senza vel, (unclouded and unveiled). Everything musically and textually points to this part of the aria; it is where most of the beauty lies in the piece. It is almost as it the voice were imitating the movement of sacred incense rising up from the oak grove, making its way to the home of the goddess in the sky. That may sound a bit much, but we arein the Romantic period, are we not? This kind of controlled excess is what many of the more serious moments in bel canto opera are all about.
Casta diva is also an excellent example of the long, elegant vocal phrases that one will find in many of the bel canto operas, especially those of Donizetti and Bellini. As these operas were generally written with specific singers in mind, Giuditta Pasta, the first Norma, must have had extraordinary breath control and the technical ability to 'spin' out a melody in a way that few of her contemporaries could match. The same must be said, too, of Giulia Grisi, the first Adalgisa. It was the abilities of singers such as these and not only the imagination of the composer that helped to stretch the limits of the operatic repertoire.
In terms of traditional Italian operatic structures, Norma abounds in examples. The entire first scene is a traditional scena with a dialogue between chorus and a father figure (in this case Oroveso) which sets the 'tone' of the opera and places it in a specific period of history.This little scena begins with a slow orchestral introduction, continues through a recitative-like exposition for Oroveso and then ends with a rousing tune, Dell'aura tua profetica (Of your prophetic spirit). This Introduction/Slow section/Fast section with chorus is a typical structure followed by many composers of the period. And, also typically, another follows for Pollione, the tenor, who enters with an attendant, Flavio. They have a recitative-dialogue within which the 'problem' of the opera is exposed: Pollione's love of Adalgisa rather than Norma, the mother of his children. A double-aria follows: the cavatina (Meco all'altar di Venere — Come with me to the altar of Venus) a dialogue interruption for Pollione and Flavio, and then the cabaletta (Me protegge, me difende — Protect me, defend me). Virtually the entire opera is a long string of these scenes wrapped around the story of the Druids and their priestess.
The third act duet for Norma and Adalgisa is a wonderful example of the double-duet, with first section in a slow or moderate tempo (Deh! con te, con te li prendi — Ah! Take them with you) which contains the heart of the duet, Mira, O Norma, and a second cabaletta-like fast section Sì, fino all'ore estreme (Yes, until the last hour). This slow/fast, two-movement structure helps to build the excitement in the drama while at the same time giving the audience a sense of catharsis at its conclusion. It doesn't hurt to be reminded that this was the era of the virtuoso, the age of Paganini and Liszt; the second, fast sections of these double-arias and double duets gave these marvelous singers an opportunity to show off their vocal prowess in ways that were more satisfying than with the musical structures that composers used prior to this period.
All of these elements make Norma a wonderful example of opera written in Italy between the 1810s and the 1840s. Its vocal demands make this opera something of a rarity today, so enjoy it! It's a great work, and well worth extra study.