Merger plans that would create the world's biggest record company are being fought by a body representing 2,000 independent labels.
The White Stripes are among the most successful independent bands
Trade group Impala is taking its fight to the European Union this week.
The group representing European music labels, says a merged Sony and BMG would take a quarter of all music sales - valued overall at £16bn.
It adds Sony-BMG artists - who would include Beyonce and Justin Timberlake - would be on radio and TV too much.
Impala - the Independent Music Companies Association - represents European music labels such as V2, Beggars and K7.
Its roster of artists includes The White Stripes, Mercury Rev and the Stereophonics.
Philippe Kern, Impala's secretary general, said the group had until Wednesday to lodge an appeal with the EU.
"We want to avoid a situation where a combined entity makes it impossible for smaller independent labels and artists to get access to broadcasters and retailers," he said.
Three years ago Impala played a major role in the EU's rejection of a proposed merger between EMI and Warner Music.
It will again argue that if the major labels join together they would squeeze out independent companies, threatening the careers of aspiring artists.
The EU's Competition Commission is expected to rule on the merger on 12 February.