Help Help HELP In bad need of help with SD card?

Hi sorry about all the Helps but is well needed. can i get back what was on an mobile phone SD card when i put the card in it is saying SD card is blank or has unsupported filesystem. the card is not mine and the music has a lot of memory for my friend she will never be able to get back, it was from her sons phone who is no longer with us. I said that i would copy them on to CD for her but not sure what i have done because they seem to no longer be on the card and not on pc.