If my mother were writing this post, it would be tagged under my Soapbox category, and it would be a vehement denouncement of the use of the semitone key lift as a device for adding interest to repeated material. There would be particular attention to the work of John Rutter, in which she contends that it is a formulaic trick, so over-used that instead of perking up her attention it makes her heart sink with a feeling of ‘Oh no, not again’.
However, I have not yet entirely turned into my mother, so I am not going to be quite so doctrinaire. But neither am I resisting the inevitable process of family resemblance, so I’ll say she does have something of a point.
I spend rather more of my time in a cappella, as opposed to accompanied, choral worlds than she does, and so my reservations about semitone key lifts are more based around how badly they are often sung. The standard quip is that their main function is to allow a flatting ensemble to end in the same key that they started in.