In the file MD_YM2413_lib.h at line 27, the define for the crystal frequency should be 3579545 which is a common TV color frequency. It's the value mentioned in the specs of the YM2413.
You are, of course, correct. This has been in the code from the very beginning so well done for spotting the extra '9'. I'll correct and reissue as version 1.1.0
In the file MD_YM2413_lib.h at line 27, the define for the crystal frequency should be 3579545 which is a common TV color frequency. It's the value mentioned in the specs of the YM2413.
define CLOCK_HZ 3597945UL