Engine/Transmission (1998.5 - 2002) odd turbo noise(music)

[new2dodge]

For about 3 months now my turbo whine(music) has had a strange sound to it. It doesn't sound like damage,i. e. growling or any thing disturbing, It just sounds different. It's hard to explain. It sounds like(pardon the wording) like it's harmonizing w/ it's self. (???) It pulls our 29" 5th great and goes down the road fine. Am I hearing things? Any ideas? egt's seem ok for blended fuel(a little higher) sorry no boost gauge yet.