I hope I haven't contravened any forum rules doing this?!
Don't think so. You're not saying anything unpleasant or for touting for business. Trying to meet up with other local families is fine. Shouldn't it be in the Wiltshire forum though?
For another taster of what's available at SHS / Marling (and local-ish to you), their school barn dance band play at Chippenham Folk Festival which is coming up over the Jubilee weekend. I think they perform mainly on the Friday at workshops for local schools but also do the main public stage in the park. Although any child of G5 up can join the band, they don't start doing gigs until Y9 (they do get paid) and the ones at the festival will be Y11 up.
Other barn dance bands are available.