I don't know about you, but I want one. They're calling them band jackets, except for the one on the bottom by Chris Benz, which has the moniker "sergeant's jacket". (The gold and cream is from him as well.)
When Chanel and Balenciaga are doing them -- first and second pictures -- you know they have the benediction of the highest order.
Since there is no such thing as high school or university marching bands in France it's a tad tricky to try to unearth a supplier or a vintage treasure. The only uniformed bands here are military related and I wouldn't know how to go about getting what they're wearing, but France being France I must say they certainly do fit well.
You have the advantage of being able to score the real deal from some high school near you -- assuming you like their colors, if not hit the Net and find a school you can support. . .
You must also search out an establishment that offers the possibility of cropped or hip-covering jackets to accommodate your figure priorities. The next step is take this fab-fashion-find to a tailor and have it fitted properly. You know, like a French woman would do under the same circumstances.