Canadian pop star Avril Lavigne has denied copying a song by 1970s rock band The Rubinoos.
Lavigne played at the T In The Park festival last weekend
Songwriters Tommy Dunbar and James Gangwer allege Lavigne's recent hit single Girlfriend was lifted from their 1979 song I Wanna Be Your Boyfriend.
But Lavigne said she has "never in my life heard of" the band and says her song has "no musical similarities".
"Their claim is based on five words," she wrote on her website. "All songs share similar lyrics and emotions."
Dunbar and Gangwer launched a legal case against Lavigne in a US District Court in San Francisco last week.
They alleged that "the lyric, the meter, the rhythm" of the Canadian star's song were "identical" to their tune.
But Lavigne reacted angrily to the claims in a message headed "to my dear media, friends, and fans".
"Simply put, I have been falsely accused of ripping their song off," she said.
"Luke [Gottwald, songwriter] and I have done nothing wrong and there is no merit to their claim."
The 22-year-old singer went on to say that the lyrical conceit of Girlfriend could be compared to other hit records.
"Off the top of my head, two other songs that I can immediately think of with this type of lyric are 'Hey, hey, you, you get off of my cloud' by the Rolling Stones and 'Hey little girl I want to be your boyfriend' by the Ramones," she said.
"As humans we speak one language."
New wave group The Rubinoos toured and recorded from 1975 to 1983 and had a hit with a cover version of Tommy James and the Shondells' I Think We're Alone Now.
They also wrote the theme song for the movie Revenge of the Nerds.
Lavigne, best known for hits such as Complicated and Sk8er Boi, recently scooped the award for favourite Canadian artist at the MuchMusic Video Awards in Toronto.
The legal case will be heard in Oakland, California, on 28 August.