What's the Temperature, Darling?

A watched suitcase never arrives.

So I told myself after waiting 'til the last possible minute to give up and walk over to the Mosque Landmark Altria Theater. A generous friend had double-booked himself, leading to offering me his Richmond Forum tickets.

Considering I woke up In Memphis, lunched in Chicago and still have no idea where my belongings are, I could have been excused for saying no thanks and spending a recuperative evening at home.

Here's the problem: tonight's speakers were Dr. Daniel Levitin, the guy who wrote "This is Your Brian on Music," a book I read despite enormous gaps in my musical knowledge, and the incomparable Rosanne Cash.

There was no way I could live with myself if I passed up a chance to hear these two talk, play guitar and sing from my friend's prime ninth row orchestra seats.

The best part was that the good doctor wasn't just a neuro-scientist, he was a musician.

As in, years spent as a session musician, record engineer and producer who worked on albums by Steely Dan, Joe Satriani, Chris Isaak and Blue Oyster Cult. That made him was way more than just a science nerd.

It wasn't my first Forum. Back in the '90s, I had a subscription to the Richmond Forum and saw all kinds of fascinating people speak: Dr. Joyce Brothers, H. Ross Perot (there's a flashback), even Bill Cosby (before, you know).

Twenty five years on, people still get dressed up for the Forum but it's become way more of a production. SPARC's spotlight ensemble was onstage singing and dancing Broadway show tunes like "At the Ballet" from "A Chorus Line" while people filed in and socialized. A soloist sang the national anthem and  we were off and running.

The evening was a conversation between the doctor and Rosanne who was participating not just because she's a musician but because eight years ago she was diagnosed with a rare brain disorder, had surgery (the drill bit broke while the doctor was drilling into her skull) and had to fight her way back to playing, writing and singing.

We heard a fair amount of science explained tonight, fine by me because I could stand to know more. Music serves an evolutionary purpose. Music releases a chemical in the brain called oxytocin (this got applause when mentioned). "It's a very pleasurable chemical," the doctor said.

There was humor, too, like when Rosanne said that music was currency in her family. "It's cash, you might say," the doc quipped. "Boy, I lobbed that one right at you," she laughed before telling a story about her famous father sitting in with her at the second Clinton inaugural.

When they got ready to do their first song together, "Blue Moon with Heartache," it took a minute to get the volumes right on their guitars. "Turn me down, I sound like Megadeth Lite," Rosanne said with authority.

She was very dry and funny, bossy sometimes to the doctor and almost making fun of his wealth of knowledge at other times. They were both completely engaging, with each other and the audience.

She made the point that a musician's song subject matter changes as she gets older. For her that meant writing more third person songs, more observations. "You're a better singer at 50 than you are at 30 because your whole life shows up in your voice."

I loved the visual imagery when the doctor talked about how Coltrane's musical ideas were too big for that little horn he played. "You could hear them just struggling to get out."

They played together on the moving "Etta's Song," about the 65-year marriage of one of the musicians in Johnny Cash's band and his wife Etta. "They started every day saying 'What's the temperature, darling?' and while she wasn't sure if the question was literal or metaphorical, she couldn't resist using it as a lyric.

The doctor told us the guitar he was playing was from Guitar Works and he loved it, while Rosanne shared that she'd gone to Plan 9 today for Record Store day. I'm sorry I missed that.

The room melted when they did "Seven Year Ache" and then it was intermission. During the break, people could write down and submit their questions for the Q & A afterwards.

I was surprised that so many questions were directed at the doctor but Rosanne had her share, too.

First musical memory? Running circles around the living room while her mother played "Hit the Road, Jack."

While the doc was explaining how we are able to store lyrics and musical information, he used the example of remembering obscure things such as Iron Butterfly's songs? "Innagadadavida," Rosanne shot back. "Well done," he said, clearly impressed.

"I'm old," she said to explain her wide-ranging knowledge. She'll be 60 next month, a fellow Gemini and still very attractive, tonight in a country-looking black shirt and skirt ensemble with spangles on the skirt.

I have to say the audience asked some thoughtful questions that garnered informative answers. The doc said countless studies have shown that, contrary to popular opinion, listening to music makes us less productive except in the case of manual labor and endlessly repetitive tasks.

And how about this: 5-10% of the population do not like music in any form. That's a really hard one for me to wrap my head around The doctor said it's an evolutionary thing; we can't all be alike or one microbe could wipe out the entire population. Count me thankful not to be in that 5-10%.

Or this: Music has been proven to be as effective as Valium in pre-operative situations and has fewer side effects. The doctor was a thoroughly fascinating fellow, smart, musical and very funny.

As if she hadn't already, Rosanne won me over completely when she talked about the exchange of energy between her and the audience, saying a performance was half her and half them.

"Some nights I look out and see the lights of people's phones scattered throughout the first six rows and I think, oh, it's going to be one of those nights." Believe me, Rosanne, there are those of us in the crowd who hate it as much as you do.

After the last question, she said, "We're going to send you off with one of the great folk songs," and they both picked up their guitars and began playing "500 Miles." Her voice was so ethereal and his harmonies so well-timed and subtle that I actually got goose bumps listening.

That, my friends, is why I had to go out tonight instead of sitting around waiting for my suitcase to arrive.

And, as luck would have it, it just arrived anyway, finally, at 11:45 p.m. Stick a fork in this day. I'm done.