Apple (AAPL 0.64%) Music does not need to take a single one of the 20 million paying members Spotify claims to have in order for the new streaming service to be successful. It simply needs to convert people like me -- iPhone users who have been resistant to the idea of paying a monthly fee for music.

Apple sold nearly 170 million iPhones in 2014, according to Statista, and has more than 300 million people actively using various models of its smartphone. Even if the full 20 million paying Spotify customers are also iPhone users (an impossibility), that leaves Apple approximately 280 million iPhones users to market its new streaming music service to.

To do that, and to spur CD loyalists like me to give subscription-based streaming a try, Apple is offering a free 90-day trial to anyone with an iPhone who wants it. I signed up and discovered that the service has some strong plusses, but also some glaring problems. I'm not comparing it to Spotify -- which I have played with a bit on an unpaid account. I'm writing about Apple Music for the hundreds of millions of users who are new to unlimited streaming music subscriptions and the idea of listening to whatever you want (mostly) without actually owning anything.

The good: It works really well in my car
I have unlimited data through my wireless phone carrier, so I'm not concerned about the expense of streaming music live while driving. Apple Music does allow people to download songs, but it streams so flawlessly that there was never more than a slight delay before a song played. In fairly extensive use, I never had a song stop, nor did I ever feel like the music was taking time to load or buffer.

The bad: The music selection
My taste in music runs somewhat away from the mainstream, but it's not so obscure that I would expect Apple Music, or any other streaming service, to be missing big chunks of it. The service has

A look at the Apple Music "My Music" screen.the full catalogue of albums from The Replacements, but an add selection of the solo music from its frontman, Paul Westerberg. It has his b-side collection but does not have his solo "hits" album the full catalog of albums from The Replacements, but an add selection of the solo music from its front man, Paul Westerberg. It has his b-side collection but does not have his solo "hits" album 

the full catalog of albums from The Replacements, but an add selection of the solo music from its front man, Paul Westerberg. It has his b-side collection The Resterberg but does not have his solo "hits" album Besterberg. 

Those holes are similar when I examine other bands that are among my personal favorites. Apple Music has all of the albums, and even some obscure releases by Buffalo Tom, but none of the solo output of its lead singer, Bill Janovitz. It's a peculiar selection with no rhyme or reason that sometimes left me wanting to hear a song and finding it not there.

The ugly: It's not that intuitive
The interface for Apple Music leaves a lot to be desired. It's easy enough to find music and add it your personal collection (My Music), but actually playing it can present some challenges. Selecting a single song or album is easy, but everything else appears to be built around playlists, which I don't generally have much interest in making.

It's possible to play an album on shuffle with a single button push, but I have yet to discover a way to play my entire collection in a random order. It may be possible, but it's not intuitive in any way if it is.

Apple has also built a nice discovery engine where users click off choices like "Classical," "Pop," or "Classic Rock" and the service builds choices for them. It also has its own pre-made playlists and a radio station. All of those seem nice, but they're not products aimed at someone who already knows what music he likes.

When it comes to playing things from my collection in a way that is not album-based, the Apple Music controls are lacking. There's a feature called Up Next, which appears to accomplish some of what I'm looking for, but the lack of any sort of explainer text or documentation makes it hard to know.

That generally has not been a problem with Apple products. I use an iPhone, a MacBook Air, and sometimes an iPad without any sort of a manual. Apple Music, however, could have used one, and the company needs to make the next iteration easy to use for people with pre-existing taste in music.

It's still a pretty good deal
While the missing songs and poor controls are a problem, overall, it's hard to argue with Apple Music at $9.99 a month ($14.99 for family plans). Basically, for the price of a CD each month (which is probably roughly what I purchase), I get access to most of the songs I want, including new releases, in a service I mostly know how to use.

It's not perfect by any means, but it's pretty good, and the value outweighs the problems -- especially when you assume Apple will ultimately correct them.