It very rarely works unless a mistake has been made
You appeal because you think the admissions policy hadn't been properly applied in your case, not because your daughter likes the music lessons
Why do people keep posting this rubbish (and worse, "correcting" people who give correct advice).
This is not an appeal for an infants class. This is for secondary school. The rules are different, which is why almost 25% of appeals for secondary school are successful. In 2018/19 (the most recent statistics available) there were almost 7,400 successful appeals for secondary schools. LAs don't always get it right but they don't make that many mistakes.
RedskyAtnight is absolutely correct. Whilst you can win a case by showing that there has been a mistake, at secondary school level you can also win by showing that the disadvantage to your child from not being admitted to the school outweighs any problems the school will face from having to cope with an additional child.
You need to look at what this school offers that is missing from the allocated school and that is particularly relevant to your daughter - subjects, extra-curricular activities, societies, etc. So, for example, if your daughter is musically talented and the school you want has lots of musical activities, that should be part of your case.
Remember you are appealing for the school you want, not against the school you've got. Remember also that your case must be about your daughter's needs. Far too many parents talk about things that are problems for them but aren't a problem for the child (e.g. needing to get two children to different schools).