One small note that I've made is the fact that the charm song now lasts
longer than three ticks occasionally. There's one of three possiblities for
this.
1. Level - It may be that as you level, as with other songs, Solon's tune
grows in strength ( ie duration of the charm)
2. Charisma - I've acquired two opalline earrings over the past 6 levels or
so, boosting my charisma by 10 points, so perhaps as with an enchanter
charisma effects duration of and resistance to charm
3. Lag - ever since Rallos has moved to CerfNet or whatever isp currently
supports its connection, we've been plagued with packet loss no less than
1.6 % and occasionally as much as 30 % all constant. Could be it just
isn't updating the charm wearing off as quickly as in a lag free
environment.

I remember when I was level 24, I inquired about this song on this list and
someone told me it only works on mobs 25 and under due to the relatively
recent charm changes. That is not true, it works well with even red mobs
occasionally. It's my only real defense against Hill Giants because, as you
had said, the range on this sucker is incredible. Soon as a Giant gets
within bellow range, that's just about enough range for them to hit me.

Another thing to note is, just as with any other charming spell, the mob
will not leave you alone once it's been charmed. I've twinked my friend
quite a bit with the help of this. -=)