掲示板 Forums - What would be the proper way to phrase this?

Hello! I was answering the following question in the question corner: 着物を着たことがありますか？

And due to my memory being a bit lacking, I wanted to say that I wore a kimono during an opera as a child even though it was in fact only my sister who wore a kimono, I was wearing something else but I was so focused on figuring out all the vocabulary and grammar needed for my sentance that I completely blocked that part out haha. Maybe it was because I didn't like dress I had to wear very much

Anyway, this is the sentence I ended up piecing together with the help of the on-site dictionary before I remembered that the whole thing was in fact a lie: はい。子供の時,子供のオペラ合唱団に合唱しました。オペラパフォーマンスに数回着物を着ました。

And I was left with this question: is there a better way to express that I (even though it was actually my sister...) wore a kimono for the performances of a specific opera, rather than for a few "random" opera performances? I'm not familiar with very many different counters yet, so I'm not sure how to say "one opera (but multiple performances of that opera)" or if any other grammar should be used to convey this etc. Tysm for any tips