There are two famous composers with the name Scarlatti. Today, the son Domenico Scarlatti is the more well-known, in particular for his keyboard sonatas most of which were not published until after his death. During their lifetimes though, it is the father Alessandro Scarlatti who was the more famous, known by other composers, musicians and by audiences across Europe as a celebrated opera composer. Alessandro had two sons. In addition to Domenico, Alessandro had another older son "Pietro Filippo Scarlatti" who also became a composer.
Although born in Palermo, Sicily, Alessandro started his studies in Rome under Giacomo Carissimi whose guidance helped Scarlatti to compose his first operas. For a while he was the "Maestro di Cappella" for Queen Christina of Sweden, who was living in Rome at the time. He then accepted an appointment as maestro di cappella to the Viceroy of Naples and, through further posts and appointments in Naples and elsewhere including back in Rome, Scarlatti composed and guided the production of a great many operas and became a major influence on the development of "Opera Seria" (Serious Opera, as opposed to the more lighthearted "Opera Buffa" or Comic Opera). Though known as an opera composer, Scarlatti composed other related forms including oratorios (sacred operas), hundreds of Cantatas (smaller dramatic presentations), motets and madrigals (which are song forms).
Although known primarily for these operas and other choral works, there are also a number of surviving manuscripts of Alessandro Scarlatti's chamber and keyboard works. Among his keyboard works is Alessandro's version of the Spanish Folies and it is available on mfiles as an example of his music which is more accessible than his operas.
Today, the music of Alessandro Scarlatti seems to have fallen out of favour, and there are not so many performances of his music. Operas can be difficult and expensive productions to stage in any case. However there are some recordings of his music available, and here are some which you will find on Amazon: