Druleigh

Hello! First time poster. I am not sure if this is a bug or not, but I noticed that once I install forge the new in game music that was added I believe in 1.7 and 1.8 no longer plays. Instead its seems to revert back to the old music that played in like 1.6 and 1.5. Is this a bug? Is this on purpose? Or maybe its something I can fix? Any insight would be great! I've been looking online but haven't found an answer.