Fans astonished to hear the truth behind renowned 70s rock band AC/DC’s moniker.

AC/DC, the renowned rock band starring Angus Young, Brian Johnson, and more, have been belting out classics for nearly 50 years—but some fans have They’re a global sensation, but despite 51 years in the spotlight, some fans have just recently discovered the true meaning behind AC/DC’s moniker. The Australian rock legends, formed by brothers Malcolm and Angus Young, have a star-studded lineup that includes lead guitarist Angus, bassist Cliff Williams, drummer Phil Rudd, vocalist Brian Johnson, and rhythm guitarist Stevie Young, who is also Malcolm and Angus’ nephew. The band will perform at Croke Park tonight, their first Irish gig in nine years.

With a career dating back to 1974, AC/DC has won 17 accolades and had 50 nominations for prominent events such as the Grammy accolades, ARIA Music Awards, iHeartRadio Music Awards, and MTV Video Music Awards. However, there appears to be some disagreement among their fan base about their musical genre – some believe it’s hard rock, while others argue it’s heavy metal or blues rock, according to the Irish Star.

The band’s hit repertoire, which includes crowd-pleasing songs like You Shook Me All Night Long, Back in Black, Thunderstruck, Highway to Hell, It’s a Long Way to the Top (If You Wanna Rock ‘n’ Roll), and Dirty Deeds Done Dirt Cheap, clearly keeps fans interested. However, one loyal fan had an insight while jamming to AC/DC, prompting them to seek enlightenment on Reddit, asking, “What does AC/DC actually stand for?”

While some believe AC/DC stands for ‘Anti-Christ/Devil’s Child,’ the true story behind its name is significantly less terrible. When Malcolm and Angus were looking for a catchy name for their rock band, their sister Margaret noticed the letters AC/DC on her sewing machine’s power connector. It stands for alternating current/direct current electricity, which the siblings thought was an excellent fit for their band’s spectacular performances. While fans in the United Kingdom and the United States refer to them as AC/DC, they are better known as Acca Dacca in Australia. Fans have been vociferous over the name’s origins, with one stating, “I thought it meant Alternate/Direct Current.” Another person joked, “Angus Can Dance Cool.”