Thanks Joe great!
Since got my first iphone 5 years ago, I never used it to play music outside. Preferred the old clicking ipod. But that no longer works because of the new IOS, forced obsolescence.

So that is why never aware or thinking, until last week, hey am I being charged data just running around outside. So thanks, I went in Music, settings and turned Cell data off.

So you have the cell data turned off for music? If so, then Apple does not do the substitute/ music swap? Of course don't need that if you have actual mp3 on the iphone. Maybe one day if I stream, which I don't do yet, I would have to switch that back on?

Finally, isn't bummer that they change name from itunes to Music. I mean, music is a pretty generic term, so talking about the app now, kind of hard.