This allows the programmer to retrieve the first of the movements with the specified properties. Call "GetFirstMvt" to get the file number of the first movement in the list. The result return a boolean true if it found.
This allows the programmer to retrieve a complete list of movements with the properties specified in "GetFirstMvt". Call "GetNextMvt" to get the name of the next movement in the list. You call this after calling the "GetFirstMvt" function. The result return a boolean true if a new movement is found and false when the list is exhausted.
This must be called after finishing with the list. If this function is not called at the end of the list any subsequent calls to "GetFirstMvt" or "GetNextMvt" will return false.