The show plays twice more on Tuesday, March 26 at the Morris Center, and there are currently some seats remaining.

Sheehan is up first — a glowing, radiant hour of music. Sheehan is performing an abridged version of her current act exploring the history of the Great American Songbook, with the songs woven together by the public history and stories of her private history growing up in St. Louis, discovering her love for cabaret, and eventually performing. I thought that at times the conversation felt a little too forced, a little too sincere; by the end of the show, I was wishing she’d dispense with the prepared banter and just chat at will between songs. But the crowd ate up the act, so take your occasionally-jaded reviewer with a grain of salt.

But what a voice Sheehan has. “Time and again I’ve longed for adventure,” she began — the gorgeous Kern/Hammerstein collaboration “All the Things You Are.” And then she reached even farther back in time to Shelton Brooks’ “Some of These Days.” Accompanied by pianist and music director James Followell and bassist William Ellison, Sheehan pulled emotion unexpectedly from the simplest lines in various standards, but I was especially impressed by a couple of her final numbers — contemporary cabaret songs by Susan Werner, especially “I Can’t Be New”.

The second half of the show belonged to the sultry, saucy Jane Monheit, who was joined by pianist Michael Kanan, bassist Neal Miner, and drummer Rick Montalbano. The acclaimed jazz vocalist’s selections included a little Brazilian music and “I Won’t Dance”, originally recorded as a duet with Michael Buble. “Born to Be Blue” was another standout.

But Monheit really reached me with — I can’t believe I’m about to say this — an incredibly rich and moving rendition of “Over the Rainbow.” Monheit noted that her band has eight arrangements of the song, and I don’t know which of those we heard tonight, but I’ll take it any day. She found unexpected phrasings and tempo shifts that made an old trite song like that suddenly come alive with real emotion, even pathos.

And she also did the best versions I’ve ever heard of Hoagy Carmichael’s “I Get Along Without You Very Well” and “Sing” (“Sing, sing a song . . .”).

Unlike Sheehan, Monheit casually introduced her songs and riffed spontaneously as the mood struck her.

“I used to be a perfect little jazz princess,” she said near the end, “but not anymore.”

Thank goodness for that.

Curiously, while both Sheehan and Monheit talked about Johnny Mercer, neither sang any of the famed Savannahian’s songs. Also, oddly, each singer referred to herself as a “nerd” at some point in the set.

There are lots of words I can think of to describe the ridiculously gifted performers, but “nerd” is nowhere on my list.

For more on the performance, check out Bill DeYoung’s review in Connect Savannah.