A roving life

Born the year after Mozart died, his childhood was comfortable and easy, but ‘during the next 20 years (from 1808) this genial lazybones was to compose more than 40 operas’.  Prolific? "Give me a laundry list and I'll set it to music." In this time he reigned in La Scala, Venice, Naples and Rome, then left Italy in disgust at traditional opposition to innovation, and via Vienna (to meet Beethoven) arrived in Paris aged 31. He died there aged 76. More on his life and music. At his death, Verdi wrote, “A great name has been lost to the world! He had the widest reputation, the most popular of our time, and he was the glory of Italy!”

“Monsieur Crescendo” the king of Bel Canto

The fashionable genre was opera buffa (comic opera), but Rossini had already broken with tradition. ‘He embellished his melodies (he was the true creator of bel canto, a florid style of singing), animated his ensembles and finales, used unusual rhythms, restored to the orchestra its rightful place, and put the singer at the service of the music.’ Biography from Britannica.  He tried to reform opera seria (voice-oriented “serious” opera) too,
challenging the formulaic type of 18th century with  a more dramatic and melodious Tancredi (1813).   ‘His taste in women also became artistically important, as he and the prima donna Isabella Colbran began an affair which was to culminate in marriage in Bologna in 1822. He wrote music to suit her florid, dramatic style of singing all the years he was based in Naples, and this is a distinguishing trait of his opera seria.’ More  from classical.net.  ‘For a long while Rossini hoped to modify his style: to replace the comparative artificiality and coldness of florid opera coloratura with declamatory and lofty singing—that is, with truth and intensity. In order to do that, he also had to reform the orchestra and give more importance to the chorus…  Then he decided, at age 37, not to write again for the theatre. Tell was to have been the first of five operas for the Opéra, but the new government following the Revolution of 1830 set aside Rossini’s contract.’ (Britannica again)
Gioacchino Rossini (1792-1868)
“Above all, make a lot of Barbers”, Beethoven is said to have advised him.