In Friday’s early hours, Spotify and Apple traded potshots in their ongoing battle over the App Store.

That conflict centers around Spotify’s longstanding complaint that Apple charges excessive fees, routinely blocks Spotify upgrades and unfairly promotes its own streaming service in its App Store; early Wednesday, Spotify lodged an anti-competition complaint with the European Commission over the matter and CEO Daniel Ek sounded off in a blog post.

In the wee hours of Friday, Apple hit back with a sharply worded blog post that said the music streamer had cloaked its “financial motivations in misleading rhetoric about who we are, what we’ve built and what we do to support independent developers, musicians, songwriters and creators of all stripes,” although it did not substantively address Spotify’s claims or even mention the European Commission.

Apple also took a broader swipe at Spotify’s unified appeal (with Amazon, Google and SiriusXM/Pandora) last week against the U.S. Copyright Royalty Board’s decision to raise rates for songwriters: “At the same time, they distribute the music you love while making ever-smaller contributions to the artists, musicians and songwriters who create it — even going so far as to take these creators to court.”

In a response to Apple’s response, late Friday morning a Spotify rep said: “Every monopolist will suggest they have done nothing wrong and will argue that they have the best interests of competitors and consumers at heart. In that way, Apple’s response to our complaint before the European Commission is not new and is entirely in line with our expectations.

“We filed our complaint because Apple’s actions hurt competition and consumers, and are in clear violation of the law. This is evident in Apple’s belief that Spotify’s users on iOS are Apple customers and not Spotify customers, which goes to the very heart of the issue with Apple. We respect the process the European Commission must now undertake to conduct its review,” and asked readers to refer to their website for details.

This war of words seems likely to continue in the weeks to come.