How am I able to get the root path of an SDcard for any one android device?

I am writing a program to search through a devices files and compile all mp3 files for the user to select from. I ran into a problem for where to start the search. Some phones have their default SD path at sdcard, while others have a path similar to sdcard/external_sd and some are even different than these standards.

I tried using Application.persistantDataPath but it just gives a string of connecting paths, so I extracted the first two subpaths from the string(usually the "/mnt" and one step into the sdcard path) but for some devices, specifically the ones with the "sdcard/external_sd" path, the search takes much longer than just linking to the path to begin with.

Is there a more efficient way to get the default root path of a devices external storage? Or is there an easy way to the the Android API functions inside of Unity?