I've owned the Lumia 640 for four months now. The lady in the shop put my card out of the old phone into this and I've been able to play my music.
There was no space left on the old card for photos so I decided to buy a bigger card and put this into the phone which asked me if I wanted to save, photos, music etc to card which I replied yes.
I then connected both phone, with new card in, and the old card through a reader to my laptop. I copied and pasted some music into the new music folder of the card.
I disconnected the phone, after asking permission, from the laptop and tried to play the new music.
However, the playlist under the music player shows the old playlist even though that card is no longer in there. So my question is, how do I update the playlist? ie. to delete folders no longer there and to read only the new folders.