When bel canto appeared

Since the bel canto style flourished in the 18th and early 19th centuries, the music of Handel and his contemporaries, as well as that of Mozart and Rossini, benefits from an application of bel canto principles. Operas received the most dramatic use of the techniques, but the bel canto style applies equally to oratorio, though in a somewhat less flamboyant way. Nonetheless, singers needed to keep the emotional drama moving forward, and so they used the principles of bel canto to help them render the repeated material in a new emotional guise.