Hi Random, I would be the same i.e. hoping DD can see the huge benefits of accepting her original offer and go for music - really varied, interesting course, which very few are eligible to study, given the rigorous entry requirements. The transferrable skills gained must be at least comparable to English/History, with even greater career options, if anything. (Added to this, it sounds as if your brilliant DD has landed a place at Univ/Castle(??) - definitely the most sought-after;
- DS wanted to go there, but has now embraced the idea of the modern one he has been allocated!)
On the other hand, I can sympathise with you DD: it's a more demanding course than her other choices, and the thought of plunging in come October is probably daunting. However, she has done so well to get in - especially to the university she has been offered - and they wouldn't have accepted her if they didn't think she was good enough. (Also, as she probably already knows, there will be lots of history-based modules, as well as the option to take modules from other departments later on).
On Friday, while DS was making his mind up, we looked in depth at what the uni has to offer and were hugely impressed by the pastoral and support system in place; it's certainly not a place where they're left to sink or swim. Remind your DD that the IB will have made her more able than most to cope with the demands of university study, while the collegiate system will make her life much easier, particularly in first year - (this cliched it for DS, particularly when I pointed out how much time commuting/self-catering/generally fending for himself would take if he were to go somewhere where everything isn't laid on).
Good luck - I hope your DD will be happy with her choice, whatever decision she reaches.