This week, Smash Mouth confirmed to TMZ that lead singer Steve Harwell had taken a hiatus from the band's recent live performances due to heart problems.

It is Harwell's voice that leads the Northern California act's late '90s pop-rock hits such as "All Star" and "Walkin' on the Sun."

However, to many fans' confusion, the band didn't clarify the nature of Harwell's hiatus until after employing a mystery singer for several concerts. TMZ did not identify the fill-in musician, but Smash Mouth bassist Paul De Lisle has previously performed lead vocals in Harwell's absence. Since 2015, Harwell has dealt with heart failure and cardiomyopathy — a disease that makes it harder for the heart to pump blood.

See fan-captured footage from a recent Smash Mouth performance down toward the bottom of this post.

"Steve had not been feeling well," the tabloid summarized from a statement from a Smash Mouth representative on Tuesday. "[It] forced him to miss a few performances." The band's current singer is "someone the band knows and was substituting for a few shows, but it's NOT a permanent move."

Echoing concertgoers' questions, Eve 6 singer and Twitter personality Max Collins tweeted, "ok a couple things 1) @smashmouth did you really fire your singer and B) can i be your new singer."

As of this posting, it appears Smash Mouth have yet to address the singer swap online. In the past, they've used social media to question their exclusion from a greatest songs list, tell a "Straight Pride" parade to "FUCK OFF," and ask Drake to sit down at NBA games.

Last year, Smash Mouth played South Dakota's Sturgis Motorcycle Rally amid a surge in COVID-19 cases. The rally resulted in multiple new infections, per the CDC.

Smash Mouth, "All Star" (Live - Sept. 24, 2021)

Smash Mouth, "Walkin' on the Sun" (Live - Sept. 24, 2021)

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