After dinner to the theatre of S. Carlo to hear Jomelli’s new opera rehearsed. There were only 2 acts finished, but these pleased me infinitely. The overture was short, and rather disappointed me, as I expected the 1st movement would have been made more of, but as to the songs and accompanied recitatives in general they are all good – as I don’t recollect one that is so indifferent as not to seize the attention except a short bravura before the duet. The subject I believe is Demofonte – the names of the singers as yet I know not, except Aprile the 1st man and Bianca the 1st woman who have both great merit. The former has rather a weak and uneven voice, not constantly steady as to intonation – but has a good person, a good shake, and much taste and expression. The latter has a sweet and elegant toned voice constantly in tune with admirable portamento – I never heard anyone sing with more ease or in a manner so totally free from affectation. The rest of the singers were all above mediocrity: a tenor with both voice and judgement – sufficient to make one attend – a very fine contr’alto – a young man with a soprano voice, and way of singing full of feeling and expression, and a 2nd woman far from despicable. Such performers as these were necessary for the music, which is in a difficult style more full of instrumental effects than vocal - sometimes it is rather recherchée, but admirable in its tout-ensemble - learned often in modulation, and in melody full of new passages. This was the first rehearsal and the instruments were rough and unsteady, not being as yet certain as to the exact time or expression, but as far as I am yet able to judge the composition is perfectly suited to the talents of the performers, who tho' all good, yet not being of the very first and most exquisite class are more in want of the assistance of instruments to mark the images and enforce the passion which the poetry points out.