I assume the SD card will be set up on some other device and just installed in the Arduino to provide it with the tracks.
In that case I suggest that you include a text file on the card which contains display name / file name pairs. You could do that quite easily by putting each mapping on a separate line (terminated by a newline) and encode it as filename;display name. To avoid trying to hold lots of data in memory, only process the mapping file at the point you need to actually display the display name and design your sketch so that you process the whole file just by reading through it line by line and processing each line as you read it. You can use strtok() to separate the filename and display name parts from each mapping line.