The sobering news from The Telegraph this morning is that this could be just the beginning. It quotes legal experts who suspect the EU may not stop at music and could be persuaded to examine other services where it makes money through it app store from companies it competes with.
The Spotify complaint is that Apple takes a 30% "Apple Tax" from subscriptions via the App Store. This, it says, is unfair because the service competes directly with Apple Music.
Even if Apple Music paid the same charge, it would effectively be one part of Apple paying another.
Anyone who has ever tried to change their subscription will know it is very difficult because there is a turf war between, in this case, Spotify and Apple over who owns the customer. This can go on years after the initial app download, and means there is an indirect relationship between a streamer and Spotify if they arrived as a customer through the app store.
As always with the tech giants, we have a situation where making companies visible and accessible through an app store, or search engine if you're talking about Google, can lead to trouble when you then go on to be a rival service.
So music streaming is going to be looked at, and it will be interesting to see whether the experts quoted in The Telegraph are correct and Apple's News and TV operations are included in a wider investigation.
My money would be on a broader examination, because the issues in each sector are similar and it would make sense to consider them at the same time.
Apple has managed to stay out of the EU's headlights for the past few years. While Google has received a trio of multi-billon dollar fines, Apple has mostly caught the attention of the EU tax man, being asked to pay 14 billion Euros in back taxes to the Irish government.
This latest investigation is a departure and puts Apple squarely within the EU's anti-trust investigation 'cross hairs', right alongside Google.
As it launches a range of "+" service updates, that cannot be a comfortable place for Apple to be. Some experts will say the EU has it in for the American tech giants, while others may argue that these companies never learn the lesson that you cannot provide a service for people you compete with unless you can show no preference to your own service.
Whether it's Microsoft of old or Google's Android and search services of today, it's an expensive lesson to be the wrong side of.