Why won't it play music on microSD card?

So many responses would have seemed helpful years ago, when these products were new an people knew less about them. But I’ve had the thing for years, and have obviously been using it. Once it stopped working the way it always had, I’m not inclined to suspect I had suddenly forgotten how to add music, what type of music it played, or how much music the thing would hold. Again, I’ve had it for years.

The micro SDHC card was bad. I bought a new one, 8 GB SanDisk class 4, and it does not exhibit the same problem. The player “sees” every song I put on it.

So there it is.