They walk on stage and test their guitars, checking their microphone levels and such.

Brad Paisley seems happy with the settings while John Mayer seems more picky, asking for less on the vocals, more on the guitar and so on.

"You can tell which one of us is the rock star," Brad deadpans.

And so we attended another taping of CMT's program Crossroads, which takes an artist from the country world and pairs him or her with someone from the rock genre. A mix of CMT and MTV, which isn't such a stretch when you know both networks fall under the Viacom/MTV umbrella that also includes VH1.

They start off with "Why Georgia," a song I love for its imagry of a leisurely drive on a sunny afternoon with no plans or commitments that can't be broken:

I am driving 85 in the kind of morning that lasts all afternoon
just stuck inside the gloom
Four more exits to my apartment
I am tempted to keep the car and drive
and leave it all behind

Brad starts off singing the first verse with John's accompaniment on acoustic guitar. I love the soft, guitar-driven intro to this song and then the launch into a full-band-backed chorus after the first stanza. It goes from acoustic and vocals to bass, drums and backing voices, a perfect show-starter.

Brad and John traded verses and choruses, with John taking the bridge while his hand flew across the strings so fast I could barely see it, then slowed down to just his fingers moving while picking the slower parts. I don't know much about playing guitar other than the very basics I learned in third-grade music class, but John's playing amazes me. He gets noticed so much for his looks, his voice and his songwriting that his ability as a guitar player is overlooked.

We get treated to the song twice, because this is for television, after all, and they must get it just right. The vocals weren't quite right, the guitars were off, and the second take is noticably smoother.

"Judges give Brad Paisley four stars," John jokes in a low monotone. "Judges give John Mayer three-and-a-half stars.

"This is like American Idol. I'll be Simon: [in a solid English accent] 'You are a disgrace.'"

"You've got the shirt for it," Brad offers.

For the second song they trade their acoustic guitars for electric ones, Brad's featuring a paisley design and John's looking pink under certain lights but purple under others. He's got musical notes on his guitar strap. How original. They play "Bigger Than My Body," another great song for appreciating John's guitar playing when performed live.

Before the show, the executive producer joked that, despite their different musical backgrounds, Brad and John are quite similar in personality and other ways to the point that they showed up at rehearsal dressed in similar clothes, then showed up at the shoot in different, yet similar clothes. They're both in blue jeans and black t-shirts, though, which seems to me like good odds for a coincidence in the first place.

Because each singer is playing with his own bands, there's a longer lull as the roadies set up different guitars and equipment for the different musicians. After the second song, while they prepare for Brad's band, John fills the silence (as he does throughout the night) with a dry wit and comments seemingly from out of the rafters.

"Tell them what you said during rehearsal," Brad says, looking to his left at John.

"I don't think so," John replies, laughing. "I apologize to anyone Brad tells that story to."

But then he decides, "If you're going to hear it, you're going to hear it from my mouth.

"I told Brad earlier that I was looking forward to the crossover exposure we'd get from doing this. I said he could become popular with 15-year-old girls and I could become popular with 15-year-old fathers."

That's when I turned to Casey and said that when they air this show in May, they should roll the credits over clips of the two musicians talking, shooting out comments and one-liners, rather than over footage of a song.

With Brad's band set up, they play his song "That's Love." Before the fourth song, "Little Moments," John talks about how songs can often be a framework because they won't be played or sung the same way by different artists, or even on different nights by the same artist. He calls it "a great song, no matter who is singing it."

During another long break while John's band returns, the two chat with each other and with the audience. Then he comes around to talking about "No Such Thing" and then goes into it on his acoustic guitar -- until the director walks up to him on stage, stops him, and points to his bassist standing there while the roadies continue to set up for the song.

"You'd think someone would've said something to me," John jokes. "It's like, if you saw your friend about to ski down a black diamond with two left boots on. Would you say, 'See you at the bottom!' or 'Hey, maybe we should go get a Snapple or something instead.'"

After the song, John reaches down for another drink from his bottle of water. The ballroom is silent and Brad watches.

"I'm hydrating like a rock star here, Brad," he says. "Please forgive me."

Then Brad compliments John on his Heavier Things album: "I bought it the week it came out, in fact." His favorite song on the album -- though he cautions the audience never to say to a musician, "You know which song is my favorite?" because they all should be your favorites -- is "Daughters," on which he takes the lead. It's another song that requires two takes.

"Hey Brad," John says after the song. "When people say they like everything but country, why do you think they say that?"

This is what I mean when I say they should use their banter during the credits.

Brad gets his revenge though. When John leaves the stage, he uses the solo time to roast him.

"John had to pee, that's why he's gone. ... He knows he's a rock star. Before he gets to town, he asks for like three different kinds of live animals in his dressing room. Like this time, he wanted hampsters. [Audience groans.] No, not like that. He wants a male and a female hampster. Let's see ... he wanted an iguana. Where are you going to get an iguana in New York? And what else did he want this trip? Oh yeah, he wanted a tribble, which is some animal that doesn't exist. He saw it on an episode of Star Trek."

I've said over and over -- probably after every post-concert entry on this site -- that there are just some songs that don't do anything for me on the album, but when heard live have a whole new life and meaning to me. I heard John Mayer's "Come Back To Bed" in August before the album had come out, and I didn't think much of it. Didn't do much for me lyrically, in particular, and I didn't know what to think of it on first listen. When the album came out, that didn't help the song's cause. But last night it became a great live song for me because John -- as he did in August, but I couldn't appreciate it then -- goes off on a wonderful guitar solo that would make his hero Buddy Guy proud.

We're saddled with another break while they set up stools and microphones on the floor in front of the stage and the front row for the Q&A segment. Unlike with Dave Matthews and Emmylou Harris, they set up the guitars behind the two stools. John and Brad return from backstage and sit down on the stools, putting their guitars in their laps. Radney comes out and takes his seat and while the technicians continue their setup, the two start strumming their guitars. At first it's a simple, soft melody not unlike the instrumental music you might hear at a concert while people continue to file into the arena. Then John does a little of Paul Simon's "Train In The Distance," with vocals. Finally, he and Brad do an impromptu acoustic duet of Eric Clapton's "Old Love."

Then I wonder if it's just me or if Brad Paisley looks like Jeff Gordon.

During the Q&A, Brad plays "Me Neither" and John does "My Stupid Mouth," prefacing it by explaining his need to fill silences with something. Anything. It explains in part his comments between songs throughout the night. During the song, Brad picks up on the notes and joins in. I love how musicians feed off each other, how they can interpret another song after just a few notes and then join in and jam with little or no rehearsal beforehand.

After the Q&A, Brad's band comes back onstage for the final two songs of the night (and he dons his cowboy hat): "He Didn't Have To Be" and "Celebrity."

By the time it's over, it's been two hours since the taping got underway. Dave and Emmylou went through 10 songs (including one double-take) in about 75 minutes. Brad and John played 12 (with two double-takes) in 120. In both cases, we got our money's worth.

Even if it was free.