Songs missing in playlist on Android S4

[politzer]

I just received a replacement phone and I’m in the process of getting my songs downloaded from the computer onto my SD card. In the meantime I noticed a playlist I have on my desktop that has songs in it that are missing from the playlist on my mobile device. Why are those songs not there? I can play them on my desktop but they don’t even appear on the mobile. It might be useful to know that they’re local files that I brought over from my computer to the Spotify client. But it shouldn’t matter – the metadata isn’t even there, i.e. the song names, even though I can open the playlist on the mobile client