Released as a single in the summer of 1973, “China Grove” became one of the biggest and most recognizable hits for The Doobie Brothers. The tune about the “sleepy little town down around San Antone” with its preacher and teacher and gossipy locals eventually hit No. 15 on the Billboard singles chart.

But it wasn’t until a bit later during a stop in Houston that writer/singer Tom Johnston got an unexpected shock about the song.

“It was in Houston that I first found out that China Grove was a real town – and that was from a cab driver!” Johnston laughs. “He asked how did I know about the place to write about it, and I said ‘what do you mean? I made that up.’ When he said it was real, I said “you’ve got to be kidding.’”

In the time since, Johnston figures that perhaps in the early ‘70s when the band was “touring in a Winnebago” and driving in I-10 to or from a gig in San Antonio did he maybe see a road sign that lodged in his memory. After Little Feat’s Billy Payne played a keyboard riff and Johnston started adding words, he says the song “just kind of all fell together.” Though he adds that there is also a China Grove in North Carolina!

Audiences on the Doobies' current summer tour with Chicago are sure to hear that tune, along with other warhorses like “Jesus is Just Alright,” “Rockin’ Down the Highway,” “Long Train Runnin’” “The Doctor,” “Black Water” (sung by fellow Doobie Patrick Simmons), and likely the sole Michael McDonald-era tune they usually perform, “Takin’ It to the Streets."

Of course, audience will also hear “Listen to the Music,” the band’s first hit from 1972 that went to No. 11 and is their usual set-closer. Johnston says that he had no idea out of all their songs, this one would become more than just a hit, but a real classic rock anthem.

“That’s the one where the audience really sings along. It was the first song that helped us really launch our career and got us on the radio. At the time, I didn’t think it was going to be anything really special,” he says. “I was just glad to be on the radio! I never thought that it would become an anthem. I don’t think [any performer] really knows that when they’re writing it. But it’s resonated over the years with a lot of people.”

However, Johnston is quick to add that, despite the song’s good-time vibe, it has a serious message. “It’s really about world leaders and trying to have them get along through music rather than language because language wasn’t getting anything done,” he offers. “That was during the era of the Vietnam War, and it still applies today.”

As for the Doobies’ tour mates, he has nothing but effusive praise. “I’ve always enjoyed touring with those guys in Chicago. It’s great music that I’ve been listening to since even before I joined the Doobie Brothers. And they’re fun to work with,” Johnston says.

As to if there is any difference to the band in playing a co-headlining summer outdoor show vs. an indoor headlining show, he says it’s only different in the number of people in the audience. “Outside it could be 15-20,000 people, but in terms of the music, it’s pretty much the same. You play the best that you can and hope that people respond. That’s our job.”

The band’s last studio record was 2014’s Southbound, which found the band teaming with some of country music’s hottest artists like Zac Brown, Blake Shelton, Brad Paisley, and Toby Keith to reimagine some of the biggest Doobie Brothers songs. Johnston says that, while they weren’t always in the same studio at the same time with their collaborators, the whole experience “was a gas” and he had “no idea” that their music was beloved by those on the country side of things. They are currently at work — when they are not touring — on original material for a new album.

The band’s current lineup includes co-founders Johnston and singer/guitarist Patrick Simmons, along with multi-instrumentalist, vocalist John McFee, who joined in 1979. Those three are referred to as “principal” members of the band (and the only ones featured in official photographs). The group is rounded out by the aforementioned ex-Little Feat keyboardist Payne, saxophonist Marc Russo, drummer Ed Toth, and bassist John Cowan.

In addition to their current tour, the Doobies have a couple of big gigs lined up as part of the “Classic East” and “Classic West” events. The two-day mega concerts in July will feature the Eagles, Fleetwood Mac, Steely Dan, Journey, the Doobie Brothers, and Earth, Wind & Fire over two nights in Los Angeles and New York.

Johnston says that the band will have to do a sort of hit and run, as the night before the Classic West show they will be in Indiana, and right after they play the gig they will have to fly off to Detroit for their show the next night (though he does hope to catch at least some of Steely Dan’s set). They will have a similar situation for Classic East later that month.

Not surprisingly, many of the acts on the bill are under the management of record-industry legend Irving Azoff, whom the Doobies hired a couple of years ago. Johnston – and an awful lot of Doobie Brothers fans – hope that their high-profile champion could finally help put them in the Rock and Roll Hall of Fame, as they are currently one of the most egregious exemptions from the list of inductees.

“Yeah…we have no control over that! It’s kind of a political thing. I’m not sure the inductions are so much about music,” he sums up. “But we have new management, and hopefully things will head in that direction!”

The Doobie Brothers and Chicago perform Sunday, June 18, at the Cynthia Woods Mitchell Pavilion, 2005 Lake Robbins Dr., The Woodlands. Gates open at 6:30 p.m.; tickets are $30-$140.