Metallica brought their M72 world tour to Cardiff, Wales' Principality Stadium on Sunday, delivering a 16-song set that included a cover of a '60s classic that's banned at the venue.

The song in question was Tom Jones' "Delilah," which the Welsh belter released in 1968 as the title track off his chart-topping sixth album. Metallica guitarist Kirk Hammett and bassist Robert Trujillo performed the song as their nightly "doodle," in which they cover an artist local to the region where the band is playing. The bassist led the audience in a rousing singalong.

In doing so, Metallica managed to circumvent a ban that went into effect three years ago.

READ MORE: Metallica Albums Ranked Worst to Best

Watch Metallica Cover Tom Jones' 'Delilah' in Cardiff, Wales

Why Is Tom Jones' 'Delilah' Banned at Principality Stadium?

The lyrics to "Delilah" tell a grisly story of a man who murders his wife after he catches her having an affair with another man. For years the song served as an unofficial Welsh rugby anthem, with the Welsh Rugby Reunion routinely playing the song before international matches at Principality Stadium. Jones has even performed the song himself ahead of certain matches.

In later years, however, the inclusion of "Delilah" at rugby matches drew criticism due to its troubling lyrics. Principality Stadium removed the song from its halftime playlist in 2015, and choirs were banned from performing the murder ballad at the venue in 2023.

READ MORE: Top 10 Censored Rock Songs

"We have previously sought advice from subject matter experts on the issue of censoring the song and we are respectfully aware that it is problematic and upsetting to some supporters because of its subject matter," a Principality Stadium spokesperson said in 2023 (via the BBC).

Jones was unimpressed with the decision, reportedly telling his audience during a 2023 concert at Cardiff Castle (via the BBC), "You can't stop us singing 'Delilah.'"

"Can you imagine… Who was the man who didn't want us to sing 'Delilah'?" Jones added. "He stopped the choir from singing but he didn't stop the crowd from singing it."

Metallica Lineup Changes: A Complete Guide

They became the most successful heavy metal band in history, but not without the occasional personnel shift.

Gallery Credit: Ed Rivadavia

More From Ultimate Classic Rock