Today while riding mainly interstates my bike developed a high pitched whine. It is in response to throttle revs. As I turn the throttle the whine gets higher pitched and louder. It does this while rolling or on the center stand. Other then the whine the bike appears to be responding normally. Acceleration is fine, clutch feels the same, engine temp is in the normal spot, etc. When I let go of the throttle and the engine is winding down there are very small pops or crackles. The exhaust is clear no smoke or viewable particulates. I have not added anything new to the bike. It is a 2008 NAV/ABS with about 16,700 miles. Anyone have any ideas of what might be going on?