How do I make my hair stay the way I did it for a whole day?

I'm a white girl with blonde, straight hair, but I find it boring. I like braiding it for night, so later, I can brush it, so it will gain A LOT of volume and will be extra soft, but here is the problem... I don't know how to make it stay like that all day. It will stay for like 3 to 4 hour, but I need it to stay for my band practice which is at 6PM, monday after school. Before you tell me to braid the hair, and just go like that to school, no thank you, I'm white and I look terrible in small braids like that. I need the hair to stay that way for +- 16 hours, and I know I can't use any powder or gels, because it will ruin the softness. Any advice what could I do to make it stay soft and have lot of volume for the whole day??