Grammer joined Rachel Lindsay and Becca Kufrin on an episode of "Bachelor Happy Hour" to talk about his time as a guest judge on "The Bachelor Presents: Listen to Your Heart" and how he overcame rejection as a young artist.

For starters, Grammer said he was "really impressed" by the level of talent on "Listen to Your Heart."

"Everyone was really good. All the voices were good," he expressed. "There was a standard level of singing that everyone here is really good. There’s no doubt about it. I was really impressed."

(Jason Mraz, one of the judges for the first performance of the season and another "Bachelor Happy Hour" guest, shared similar words about the singers on the podcast last week.)

After telling Becca and Rachel that a large part of being an artist is "rejection," Grammer went on to tell his own story about persevering through negativity and hard times.

He began, "So much of being an artist or any career is knowing how to push through rejection and not letting someone else define who you are or what your worth is."

The "Honey, I'm Good" artist explained that he used to perform for tips on the 3rd Street Promenade in Santa Monica, California, which he did for four years "before anything happened to me."

He shared, "I was practicing in my apartment to go play on the street for no one. For context, that is the lowest you get in the music industry: to be practicing really hard to be playing for no one. I’m practicing my heart out and I get a knock on the door and there’s a sticky note on my door that says, 'Your voice sucks. Give up the dream.'"

Grammer did not see who left the negative note, but he didn’t let it stop him from pursuing his music career.

"The universe is telling you to stop," he said. "That stuff happens pretty consistently to the point where you get thick enough skin where you’re not being oblivious — you want to be self-aware — but it’s just a part of it and you have to push through it."

He continued, "There’s a lot of moments where you have to decide 'Am I going to let some angry neighbor take me down, or am I going to just brush that off and keep pushing through?' The same thing happens when you go to the street and you’re performing."

Grammer said he'd "perform for eight hours and there’d be hours and hours where no one would stop or drop any tips in."

He gleaned an important lesson from that: "That’s the kind of resistance that you grow accustomed to."

Now, Grammer has chart-topping songs that are certified platinum.

Monday's episode of "Listen to Your Heart" won't be the Grammer's first foray into the "Bachelor" world: He performed on Desiree Hartsock's season of "The Bachelorette" as well.

To hear the rest of Grammer's interview with Becca and Rachel, be sure to listen to the rest of the "Bachelor Happy Hour" episode now. Don't forget to subscribe on Apple Podcasts, Spotify, or wherever you listen to podcasts. Plus, always remember to "keep your head up"!