Putting pianists Marcus Roberts and Ellis Marsalis together on stage must have been a promoter’s fantasy: Marsalis, the patriarch of jazz’s fiery first family, handing the baton to son Wynton’s chief deputy, Roberts, the future of jazz piano.

The only question was, would they make good music together?

Saturday night at the Maine Center for the Arts, Roberts and Marsalis drowned out that question in the first few bars of Fats Waller’s “Jitterbug Waltz,” and launched into two hours of jazz that was virtually one solid highlight.

Individually, Roberts and Marsalis each showed virtuosity. Together, they soared through a heady musical conversation, a fascinating exchange of themes and styles and rhythms.

They stripped their art to the essentials — two Steinway concert grand pianos, nested together on a bare stage — and took a rapt audience directly into the heart of jazz, the fluid meeting of emotion and intelligence that drives the music.

From an exquisite version of Benny Goodman’s hit “Goodbye” to a dazzling rendition of Duke Ellington’s “Cottontail,” which brought the house out of its reverential silence, the pair explored the range of feeling in jazz standards. When they ventured on newer ground, such as their collaboration “Dual Blues,” it sounded no less classic.

If the sensibility was traditional, however, their interpretation held the best of both old and new. Marsalis built his solos patiently, seamlessly, running through the upper register in elegant clouds of movement.

Roberts was the lightning bolt that cut through Marsalis’ gentle showers of notes. Bringing his whole instrument to life, Roberts erupted from the lower register into powerful and surprising melodies all his own.

Without a trace of emotion on his face, Roberts played out his passion, sometimes rocking the huge piano with bluesy attacks, sometimes making it achingly quiet. It became increasingly clear that something great was at hand in Roberts’ work; even Marsalis, the veteran, raised his eyebrows in amazement and delight from time to time.

In the end, it seemed less like the performance of something already achieved than the achievement of something new, a fresh edge on jazz’s best traditions.