Re: Interesting...
"Using their large user base to move into a new market!, surely that is anti competitive and there should be a option to install a different music service instead, a bit like Microsoft where made to do with Explorer."
No, it's not anti-competitive. Apple aren't as popular as their presence in the tech press suggests, and have nowhere near the level of clout MS enjoyed in the late '90s.
In MS's case, they had 95% market share of the whole world's desktop OS market and were leveraging that for dominance in web browsing. In Apple's case, they have about 15% of the world's smartmobe market, so no matter how they leverage it they're not gonna shut out competitors. For all the giant valuation of Apple, they've never actually been dominant in any market; even in the US, where iPhones are more popular than elsewhere, Samsung and Android have pretty much always had better market share - and North America is actually a really small market (~400m people, half the size of Europe, a third the size of India and 1/4th the size of China). In global terms, it's like being the premier cheese-monger in Dudley.
If you look at the rest of their tech portfolio, it actually gets worse. Macbooks and Mac Desktops have a market share of about 10%; that's only about 3% higher than it was back in the mid-90s. Even the mighty iPod, which had over 70% of the US MP3 market every year for most of a decade, was actually below 50% if you looked at it world wide. The Watch's iPhone dependency means it's locked out of over 85% of the worldwide market automatically, which doesn't exactly bode well. iPad market share fell off a cliff the moment serious competitors decided the tablet market was a thing after all, and continues to plummet even in a now shrinking market.