My last rooster, Nightfall, and a bantam rooster who I was very close to, Chester, both would crow when I wanted them to. Chester I could get crowing in the middle of the night. What it is, I'd crow, and they'd crow back. On Nightfall, I crow once, and he'd crow back.
Both these roosters I raised around my crowing, and on Nightfall, I was chirping to when he was still in the egg. I don't know if my raising them around my crowing is what trained them, or if I'm just a really good crower and they like crowing back to me. (I also can get my neighbors roosters crowing too at times, so maybe it's just my own crowing.)
As suggested, a video might work, but an outside loud crow would work better. As far as the fair, other roosters there most likely will be already crowing. Just make your rooster feel as safe and comfortable as possible, and he'll crow too. If you're looking for practice to help him there, practice by having him in a cage like what he'd be in at the fair and practice a similar setup. That way, he's used to that setup, and will start crowing sooner and more.
Both these roosters I raised around my crowing, and on Nightfall, I was chirping to when he was still in the egg. I don't know if my raising them around my crowing is what trained them, or if I'm just a really good crower and they like crowing back to me. (I also can get my neighbors roosters crowing too at times, so maybe it's just my own crowing.)
As suggested, a video might work, but an outside loud crow would work better. As far as the fair, other roosters there most likely will be already crowing. Just make your rooster feel as safe and comfortable as possible, and he'll crow too. If you're looking for practice to help him there, practice by having him in a cage like what he'd be in at the fair and practice a similar setup. That way, he's used to that setup, and will start crowing sooner and more.