In their lawsuit, obtained by Pitchfork, Collage state that "many of the main instrumental attributes and themes of 'Uptown Funk' are deliberately and clearly copied from 'Young Girls.'"
This includes "the distinct funky specifically noted and timed consistent guitar riffs present throughout the compositions, virtually if not identical bass notes and sequence, rhythm, structure, crescendo of horns and synthesizers rendering the compositions almost indistinguishable if played over each other and strikingly similar if played in consecutively," the lawsuit continued.
A representative for Ronson declined to comment on the lawsuit. A representative for Mars did not immediately respond to a request for comment.
According to TMZ, Collage added that Mars and Ronson admitted in interviews to being inspired by the Eighties Minneapolis and electro-funk scenes that Collage belonged to. Collage are seeking unspecified damages and profits.
Ever since the arrival of the retro-sounding "Uptown Funk" in November 2014, Mars and Ronson have battled accusations of copyright infringement, including the threat of a lawsuit from funk group the Sequence, who argued Mars and Ronson's single copied their 1979 song "Funk You Up." However, the Sequence never formally sued Mars and Ronson.
In April 2015, while "Uptown Funk" still clung to the top of the Hot 100, the credited songwriters on the track quietly jumped from six (including Mars, Ronson and "All Gold Everything" singer Trinidad James) to 11 after a claim on the track was put forth by publisher Minder Music on behalf of funk group the Gap Band.
The claim, which never went to court, contended that "Uptown Funk" shared overwhelming similarities to the Gap Band's "Oops! Upside Your Head"; the chorus on both singles is nearly identical cadence-wise. As a result, the Gap Band's Charlie, Ronnie and Robert Wilson as well as two band members were added as "Uptown Funk" songwriters.
Compare "Young Girls" and "Uptown Funk" below: