I woke up early today thinking about the choir that sang last night at the LDS women's session and what an amazing and unique thing it was. Many of the women singing were not native English speakers (some don't speak much English at all) and it would have been much more difficult than usual to teach the songs to such a large and diverse group of women. The women must have worked hard to learn the songs. Since many of the women are converts with a wide variety of family support for their conversions and with a wide variety of socioeconomic challenges, I imagine that it would have been difficult for many of them to even go to the practices, much less to go often enough that they were able to learn the songs well.
Also, when choirs like these are organized (this was 350 women from 7 stakes), it's usually easy for each ward to find 5-7 women who are willing and able to participate and who have musical experience. But in this case, there would have been a much smaller pool of women to select from and everyone would have been needed, no matter her language ability or musical background. A lot of support would have been necessary.
I am thinking that there was a great deal of sacrifice involved in that choir singing last night and I am so grateful that the women singing felt that creating such a diverse choir was worth what must have been significant hurdles.
ETA: Here's an article talking about some of the challenges.