Final answer:
The elegant early 19th century vocal style known for its effortless technique and beautiful tone is described as 'bel canto'. This style highlights the singer's artistry through pure tone and controlled phrasing, especially in Italian opera.
Step-by-step explanation:
The vocal style characterized by an effortless technique, beautiful tone throughout the vocal range, and the display of agility and fluency that emerged in the early 19th century is known as bel canto. This style emphasizes purity of tone, great control of breath, and a disciplined approach to phrasing aimed at showcasing the singer's artistry and the beauty of the music itself. It became particularly associated with Italian opera, where the human voice was treated as a supremely expressive instrument and singers were trained to execute difficult passages with seemingly effortless grace.