L’amerò, sarò costante (from Il rè pastore, K.208)

Although Mozart was not quite twenty when he wrote Il rè pastore he was already an experienced composer for the theatre. He had written no fewer than eight operas, or stage works more or less of that kind, and there was no dramatic situation he was not competent to cope with. It is just unfortunate that in the case of Il rè pastore the libretto - the last he was to set before Idomeneo six years later - is not very exciting theatre. Abbreviated and adapted from a Metestasio original, itself based on Tasso’s pastoral play Aminta, it drips with noble sentiments but offers little in the way of dramatic conflict. It does, however, contain some inspired arias, including two with prominent instrumental solos, both of them in the second of the two acts - the heroic Se vincendo for Alessandro (Alexander the Great) with obbligato flute and the lyrical L’amerò, sarò costante for Aminta (the “shepherd king” of the title) with obbligato violin.

In L’amero, sarò costante Aminta sings of his undying love for his shepherdess Elisa. Although it was written originally for castrato, the tender vocal line surely blends no less well with Mozart’s poetic scoring when sung by a female soprano. Certainly, the rondo construction - which alternates the first three lines in the tonic key with two episodes based on the next three lines in changing harmonies - is just as effective either way. What the soloist makes of the opportunity for a cadenza near the end is more important in this case than the colour of the voice.

L’amerò, sarò costante: I will love her, I will be constant:

fido sposo e fido amante, a faithful husband and faithful lover.

sol per lei sospirerò. Only for her will I sigh.

In sì caro e dolce ogetto In her, so dear and sweet a thing,

la mia gioia, il mio diletto, my joy, my delight,

la mia pace io troverò. my peace will I find.