This week, ZZ Top canceled their Tuesday show in Chula Vista, California, and their Wednesday performance at the Hollywood Bowl. In a statement on their social media, the band said that “Insurmountable obstacles require canceling,” and asked that fans “bear with us for this brief interruption.”

Ticket holders are entitled to refunds at the point of purchase. All tickets, including transportation and parking passes, will be automatically refunded to the original payment method.

ZZ Top’s current tour, The Big One, still has scheduled stops coming up in Fresno, California, on Friday, and Modesto, California, and Saratoga, New York, this weekend. The band extended the tour this year with nearly two dozen new dates over the summer.

“It’s good for us and for the generations of fans who appreciate what we do,” said frontman Billy Gibbons. “We’ve been at it for quite a while—something like five decades—and it seems we’re getting good at it, so there’s no reason to slow things down. Let’s rock!”

“What is the real reason ZZ Top cancelled [the] Hollywood Bowl concert? Could it be poor ticket sales?” asked another.

Others were critical of the lack of ZZ Top drummer Frank Beard, who took some time off last year due to “foot and ankle issues” and an undisclosed medical procedure. He had since returned to playing with the band, so his absence now has fans concerned.

“No Frank Beard on drums,” one person remarked. “Is Frank gonna be there?” asked another.

Following the news of the Hollywood Bowl cancellation, Cheap Trick, who have been ZZ Top’s touring partner on select dates, announced a “very special and intimate” show at the Troubadour in West Hollywood on Wednesday. That show was almost immediately sold out.