Put a MP3 file in the Music folder on Android

Hello, I want to write un Music folder of Android. My code is:

    var fromFile = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory,filename);

                    var toFile = Ti.Filesystem.getFile("Music",filename);
                    if ( toFile.exists() == true ) {
                        toFile.deleteFile();
                    }
                    toFile.write(fromFile.read());

This dont work
I want to replace "Music" by the correct form to put the file in the root Music directory.

Thanks