Johann Adolph Hasse (baptised 25 March 1699 – 16 December 1783) was a German composer, singer, and teacher born in Bergedorf near Hamburg into a family of church organists. He began his career as a tenor, joining Hamburg’s Oper am Gänsemarkt in 1718 before moving to the Brunswick court, and by the mid-1720s had settled in Naples, where his success brought him into contact with Alessandro Scarlatti, who became his teacher and friend. In 1730 he married the celebrated soprano Faustina Bordoni and was appointed Kapellmeister at the Dresden court, a post he held for over three decades while also composing prolifically for Venice, Vienna, and other Italian centres; he spent his final decade in Venice, where he died in 1783.

Hasse was, alongside his close collaborator, librettist Pietro Metastasio, the dominant figure in mid-18th-century opera seria, composing dozens of operas and a vast body of sacred music that made him one of the most performed composers of his era across Italy, Germany, and Central Europe. His melodic, lyrical style set the standard against which the operatic reforms of Christoph Willibald Gluck were later measured, and though his reputation was eclipsed after his death — famously, on hearing the teenage Mozart’s Ascanio in Alba in 1771, Hasse predicted “this boy will cause us all to be forgotten” — renewed scholarly and performance interest since the late 20th century has restored him to a central place in the history of Baroque and early Classical opera.

Sources:

• https://en.wikipedia.org/wiki/Johann_Adolf_Hasse