A Delaware school district apologized this week after spectators at a high school volleyball match were treated to Roseanne Barr's infamous rendition of the "The Star-Spangled Banner."

In a letter to parents on Wednesday, the Seaford School District said "we apologize again for this unfortunate incident." It has opened an investigation "to determine why the national anthem normally played was not used."

The anthem was played before Tuesday's match between Seaford and Milford High Schools. Parents on social media called the incident "disgraceful and disrespectful," The News Journal of Wilmington reported.

ROSEANNE BARR SAYS FERGIE'S NATIONAL ANTHEM PERFORMANCE WAS WORSE THAN HER 1990 RENDITION

A letter from Seaford Superintendent David Perrington said the district usually plays the anthem before games to honor the U.S. and the military. He said pregame proceedings will be improved to guard against a recurrence of the Barr episode.

"In the future, the district will utilize our district-approved version at athletic events," Perrington said.

The school district also reached out to the Milford School District to apologize.

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Barr's off-key rendition of the national anthem before a 1990 baseball game between the Cincinnati Reds and San Diego Padres was widely condemned and is considered one of the worst of all time. At one point, Barr spit on the pitcher's mound and laughed mid-song.

She was showered with boos and criticized by then-President George H.W. Bush, who called her actions "disgraceful."