In all, that did not add up to a lot of music. Because musical forms were not yet codified, many Baroque compositions are titled differently than they would have been during the late 18th century of Haydn and Mozart. For instance, a Scarlatti "sonata" simply meant a short piece in two sections, averaging about four minutes. The works we know as Bach's orchestral suites, Scarlatti called "overtures." Basically, a form could mean anything the composer wanted it to.

Scarlatti, Handel, and Bach make for a fine contrast of styles: Scarlatti, the super-inventive court harpsichordist; Handel, the worldly organ virtuoso and vocal giant; and Bach, the genius stuck in provincial church posts. All wrote religious compositions, but for Scarlatti and Handel the approach was decidedly secular. Handel's oratorios, for instance, are basically operas without the costumes and sets. Scarlatti's religious works — few by comparison — are largely beholden to the Neapolitan operatic style of his father, Alessandro Scarlatti. Bach's are more genuinely religious, although they often rely on secular dance formations for their rhythmic patterns.

Scarlatti was easily the most daring and original of the three, especially in his 555 or so harpsichord sonatas. He was the Liszt of the Baroque, inventing major additions to keyboard technique that called for virtuosity even beyond that of Bach's requirements. Some of his sonatas required extremely fast, repeated notes close to that of a bowed tremolo. He is most famous for his hand crossings — one arm reaches back and forth over the other for a note or two, then goes quickly back to the normal position — a feat that is repeated any number of times in a few bars of music. He created unusual modulations that were 75 years ahead of his time, as well as amazing dissonances, and he was the first to use irregular phrase lengths that ignored the expected eight or 16 bars.

The opening sonata of this concert often sounded like a fandango, mixed with a bit of Gypsy strumming, reflecting the influence of Portugese and Spanish culture — especially guitar music and dance forms — on Scarlatti. The minuettos and minuet were tamer stuff. Possibly intended as teaching pieces for his students, they sounded ordinary to the point of being banal and cautious.

Handel's harpsichord music is not as technically demanding and aims for the public rather than the virtuoso specialists. Handel's contemporary, the historian Charles Burney, noted Handel's "sly pseudo-simplicity." That is Handel's genius: With no overt show of complexity, he can command attention with playable, delightful music that holds a wide range of feeling. A surprise in the D-Minor Suite came from the Sarabande, with two variations, instantly recognizable as the famous La Folia chaconne, a kind of Top 40s piece of the period. Handel's version is a little genuflection to the tune, and the Sarabande was the only time Stephenson used the instrument's lute stop, with lovely effectiveness.

Interestingly, the Bach works Stephenson chose are relatively minor. Apart from the little horn calls for the mail coach, the programmatic Capriccio doesn't sound like more than the work of a reasonably talented teenager.

Stephenson fleshed out his performance with charming, accurate program notes, and he took questions from the audience. He offered witty tidbits and fresh information; toward the end of his life, for instance, Scarlatti had become so fat that he could no longer play his arm crossings. Handel would flaunt his wealth by walking around London with a gold walking stick.

Besides being a virtuoso player, Stephenson is also an authority on early instruments, especially the reproduction of keyboard instruments. He discussed the 1999 Norman Sheppard harpsichord he played, explaining how the best wood was chosen for different components, why little strips of crow or buzzard feathers were used for the quills that strike the strings, and the fact that impurities have to be added to modern metals to reproduce the sound created by 18th century wire for the harpsichord's strings. Turning to the keyboard for the last time, Stephenson played not a full encore but a bit from a Bach English suite, followed by its origins in an Irish jig. A good chuckle was had by all over this bit of outlandishness.