Rob Thomas gets candid about marriage, music as he kicks off 'Chip Tooth Smile' tour

No matter your age group or musical taste — or whether you even realize it — you're probably familiar with Rob Thomas’ music.

Whether it’s the multiple hits he’s fronted for Matchbox 20 for over 20 years or through his solo albums, or even yet, through songs he’s written for artists like Willie Nelson, Mary J. Blige, Mick Jagger or Marc Anthony, chances are you’ve hummed, sung along to at least a chorus or belted out his lyrics.

As "Nightline" recently witnessed, to know Thomas is to like him, and to get to know him is to understand how this dedicated husband, animal philanthropist and all-around talent is inspired in his music and both his personal and professional life. Check out our profile here to see for yourself.

Thomas’ new single “One Less Day” recently shot his fourth solo album, “Chip Tooth Smile,” to number two on iTunes.

The Grammy Award-winning singer has written '90’s hits like “Bright Lights” and “3 AM,” beautiful ballads like “You Won’t Be Mine” and “Pieces,” including the hypnotic “I Am An Illusion,” yet even those hardly stack up to the behemoth “Smooth” written for Carlos Santana.

Though it’s been 20 years since their collaboration came out, “Smooth” still generates an incredible nearly 1 million on-demand streams per week, according to Nielsen Music. It has also remained Billboard’s number two song of all time.

“I had this relationship with ‘Smooth,’ and Carlos too, where like I'm fine if I never hear it again, but I love playing it. I love it when I do it with Carlos. I love doing it with my band,” Thomas said.

Thomas has regularly drawn inspiration for his music from his relationship with his wife of nearly 20 years, including for the songs “Pieces” and “Her Diamonds." Model Marisol Thomas has helped manage his career, and the pair — along with Marisol’s mother, Maria — run the duo’s passion project, Sidewalk Angels, which provides funds to no-kill animal shelters and rescues.

Marisol Thomas has struggled with debilitating autoimmune and multiple tick-borne diseases for years, but she said the singer has been there for her every step of the way, even while on the road.

“The last few years have been extremely hard and it's forced me to have to give up a lot of things and focus just on my health,” she told "Nightline." "It was really difficult because my life for 21 years has been the road. I'm at a place where I want to be more than just a patient. I want to be more than just a victim.”

Marisol Thomas explained that her husband “would literally be on the bus feeding dogs, giving medications, doing a therapy for me that required injections that my doctor had taught him how to do, jumping off the bus, making sure we were OK, getting in front of a stage playing to thousands of people, bringing it like nobody's business, doing meet-and-greets, get back on the bus, check on me, do more meds and walk the boys.”

She added that people “have no idea that he was doing all of this six days a week...and he did it and never complained,” she said. “He's everything for me.”

She quickly added, “I don't want to paint this fake picture that it's always sunshine and hugs and kisses. It's hard,” she said. “He's from southern roots and I'm Latin, so fights between that...it's not pretty.”

Thomas chimed in, saying, "We have fights that started 10 years ago. They're still going on. [Yet], the life we have, when it's bad, it's worth saving. And when it's good, it's better than anybody's."

“When I came into the picture, we were both really young and we created this together," Marisol Thomas said. "Everything that people see, even when he's on that stage — every haircut, every move, every song — it's something we created together for the last 20 years. We were on a trajectory and headed somewhere.”

“He's done remarkably well." Referencing the debilitating battles with her health, she shared, “But I do feel that what happened to me, literally put this halt, and I do see all the opportunities that slipped away, that he lost because he stayed with me and because he made me the priority."

“I don't believe that there is anything that's supposed to happen, that's not happening and vice versa,” the songwriter responded. “I just kind of feel like everywhere that we are is exactly where we're supposed to be. No one's forcing anybody to be in a relationship.” [That] “can only be true if someone's holding a gun to my head and making me be here."

Rob Thomas’ sensitivity, collaborative nature and appreciation for those he surrounds himself with is palpable and reciprocated.

“I've had the same management, I've worked with some of the same people for 13 to 20 years,” he said. “So like, when we're on the road, that's a little tight family that we have.”

Almost all members of his solo band have been with him for over a decade, and many of his touring staff have been promoted within.

“Those relationships are really important, I think. Our bus driver for 18 years is now our road manager because he got tired of driving buses and he wanted to try something new. So we made him our road manager. One of our best friends in the world, who just passed away, was our tour manager, but he started off as just a bodyguard and he wanted to do more. So we started giving him more responsibility. Being surrounded by people that you trust is really important to us.”