The listeners were indeed fortunate, for they heard two jazz masters crafting a performance that bristled with spontaneity. Bennett altered the lyrics of certain songs and toyed with the melody notes of others, while Brubeck invented the complex chords that were his signature.
Amid all this, however, the Tony Bennett of the 1960s sounds remarkably like the Tony Bennett of the 2010s.
"That's exactly right," says pianist Sharon, who adds that he's struck by commonalities between the singer's current work and his contributions more than half a century ago.
Stylistically, says Sharon, Bennett performing with Brubeck sounds essentially the way Bennett does today, "and he always will. … I thought they did very well. Tony is indestructible. He can sing with anybody, and that goes all the way through time."
And then there's the other phenomenon of Bennett's latter day work: his memory. Last year at Ravinia, as always, he sang approximately two dozen songs, each with the right syllable and the right note in the right place. That might not seem like such a great feat of memory until you take into account that Bennett's repertoire embraces hundreds of songs that he has been cycling through his concerts and recordings through the decades.
How does he keep it all in his head?
I once posed the question to his daughter, singer Antonia Bennett, who opens many of his shows and will do so again next week at Ravinia.
"He works on it – all the time," she told me, reaffirming the notion that the greatest artists make their work look easy, though it is not.
Tony Bennett chalks up his ability to command all that repertoire at this late date to a very different source.
"I don't sing a song I don't like," he says, meaning that the best songwriting naturally clings to memory. "I look for intelligent songs. I dislike entertainers who look at the audience like they're below them.
"I consider an audience very alert, and why not give them the best? Why not give them top quality? It's the opposite of obsolescence."
So Bennett appears to be savoring these autumnal years of his career, his touring schedule as brisk as ever, his audiences large, his desire to take and hold the stage apparently undimmed by the passage of time.
"There's not one bad review everywhere that we went," he adds, sounding a bit surprised. "So it's satisfying to know that I'm being accepted, you know?
"What I'm hoping for now, at age 87 … I'm going to try and prove that the older you get, the better you can get, by just learning more and more about what to do and what to leave out and how to keep it.
"My two heroes are Jack Benny and George Burns, who just really went through the whole thing beautifully."
Still, Bennett realizes that the pressure is always on. So he knows exactly what he's going to feel right before he steps onstage at Ravinia.
"Butterflies, right in the little tummy," he says, with a laugh. "I just say, 'I hope everything works.'"
So far, so good.
Tony Bennett performs at 8 p.m. Aug. 22 at the Ravinia Festival, near Green Bay and Lake-Cook Roads, Highland Park; $91-$101 reserved; $34-$39 lawn; 847-266-5100 or ravinia.org.
To read more from Howard Reich on jazz, go to chicagotribune.com/reich.