Between the post-audition interview with "American Idol" finalist John Foster just a few weeks ago and last week's check-in, it's clear the Louisiana teen is getting used to the spotlight.

His responses to questions are quicker. His voice more confident and relaxed. But make no mistake, the second-semester LSU student, 18, has a plan for staying grounded despite his near-overnight fame.

"I've just kind of had to make sure that I'm staying centered on myself and my faith and knowing that I have a purpose here and that's why I'm here," country singer Foster, of Addis, said from Hollywood after wrapping up a rehearsal. "And that's what's keeping me straight and that's all I can do."

On Monday's "Idol," Foster made it into the Top 3, the last elimination before a new "American Idol" is named in this weekend's Season 23 finale. That three-hour show airs at 7 p.m. Sunday on ABC and streams the next day on Hulu.

This interview has been edited for clarity and length.

Tell us about this sudden fame and skyrocketing fan base?

Somebody said one time that "American Idol" is rocket fuel, and I think that's a perfect analogy for what it can do for an artist. You know, it's been literal rocket fuel. I went from 5,000 to 200,000 followers on Facebook, which, within two months, is absolutely incredible.

Another example of kind of how far this has brought me is never in a million years did I think I'd ever be recognized in Disneyland. Like, sure, I can see somebody recognizing me in like Louisiana or you know, Texas or something, but Disneyland in California was not somewhere that I ever thought I'd be recognized in. And sure enough, many people recognized me, which was crazy. 

It sounds like you do have a little bit of time in your day to look at your social media. What is a typical day like for you these days?

I wake up usually around 8 a.m. and get to the studio (Red Studios in Los Angeles). The day consists of rehearsing, vocal coaching, trying on wardrobe — because each performance has to be a different outfit. So we're talking four full outfits for next week.

We have to rehearse every single song and coach every single song. So there's a rehearsing coach for that. During the daytime, we usually have little to no social media, but we usually get done about 5 (p.m.) or 6 (p.m.) after we rehearse and do wardrobe and all that fun stuff. The evening time is usually my time that I can kind of see what's going on on socials and reply to some people and make some posts, whatever I need to do.

You mentioned wardrobe. At any time before the end of the season, will we see you maybe without the cowboy hat or minus the guitar?

You'll definitely see me a couple, maybe one or two times without my guitar (it happened Sunday night). But my hat stays on always. I don't usually wear it very much outside of the stage, but when I'm onstage, I've had that hat on for — gonna be three years in July — every single performance and for virtually every single performance, I've had that hat on since my very first gig. So there's no way I can go on that stage without it. 

Tell us about the Cancer Foundation fundraiser you just did on Facebook?

I've got a lot of people asking for autographs, like just a signed picture — like over a hundred in my inbox or comments or whatever. I didn't want to sell anything, but also I didn't want to totally give some people autographs for free and then not others — that felt unfair to me.

So I started a fundraiser on Facebook for the American Cancer Society, which obviously holds a place dear to heart because not only do I have multiple family members that are currently battling cancer, but I aspire to be an oncologist. I figured it kind of kills two birds with one stone to be metaphorical, because we're raising money for cancer research and treatment.

Also, some people who really wanted an autograph picture of mine get one, you know? As of today, we are at $5,300, so that's really, really humbling and it warms my heart to know that people support me and in return we can support those that really need it, those that are battling and looking for a cure to cancer.

As far as social media reports, we've seen things such as your getting record deal offers from four different record companies, that you've even signed with one. Can you clarify that?

I am not signed to or affiliated with any record label whatsoever. I signed the tentative contract with 19 Entertainment, which is "American Idol's" record label (common procedure for finalists). But for clarity reasons though, no, I have not signed with any label.

It's also being circulated that your song "Tell That Angel I Love Her" has hit No. 1 on the Billboard charts and it's some kind of record.

No, that's also false information. As much as I wish that was true, I did not hit No. 1. I did like do some waves on the iTunes country charts, but that was the extent of that, unfortunately.

Have any of the artists whose songs you've performed been in contact with you?

Yes, actually, Randy Travis followed me on Instagram and sent me a very nice message congratulating me and just kind of giving me some words of support as I go along. My heart went to my toes when I saw that notification. And, of course, it's always like, I always do have to check, you know, because so many people, you know, are fake accounts. There are already hundreds of fake accounts of me, but I needed to make sure the one from Randy Travis was real. Sure enough, it was really him. That was really awesome.

You've had the chance to work alongside so many people in the last few weeks — Miranda Lambert, Jelly Roll, Josh Groban, James Taylor. What stands out in your mind as far as advice that they gave you?

To meet people who are in the shoes that I hope to be in one day — I mean, I hope to have careers like they do, and just to simply meet them and feel their authenticity and to feel like their happiness too. They all were wonderful human beings.

To know that you can go far in this industry and be under this much pressure and still be the normal good human being is really comforting to me. 

For instance, Josh Groban gave me some really good tips about anxiety and because I've kind of struggled with that in the past before going on stage — just really kind of getting in my head about different things. To know that they struggle with that too, and that they deal with that constantly is really comforting for me as someone who's trying to emerge onto the mainstream of the industry.

Just kind of being around them and hearing their experiences, it's been truly great.

Viewers in the last couple episodes have been introduced to your girlfriend, Brooklyn (Bourque). How is she dealing with all this?

She's doing great. She and her family have been watching "American Idol" since she was born. Like her dad can remember watching Carrie (Underwood, now an "Idol" judge) win. So for her to be on this show that her family has watched so much was really cool for her. She was super excited and it was just a really great moment.

People are referring to you as things like "the next George Strait." Has that sunk in?

Man, George Strait is the absolute king of country music and I have based a lot of my vocal and performance style around him because he's just so incredibly good at what he does. I mean, there's a reason he's the king of country music.

He didn't just spring into that role. So for people to even slightly compare me to him is such an honor. You know, I hope one day to meet him. I've been listening to him since I came out the womb. He's so incredibly amazing at performing and making country music — that even the slightest mention of him near my name is an honor in itself.