Competing in the Columbus East District, Clay City earned a Gold rating in Class D.
Also earning a Gold were New Washington, Monrovia, Southwestern, Borden, Crawford County and Eastern (Pekin).
Monrovia won Best Music and Best Visual while Eastern won Best General Effect.
In the Southport District, Northview also earned a Gold rating in Class B, along with Plainfield, Whiteland and Greenwood.
Northview also tied with Whiteland for Best Music. Greenwood won Best Visual and Best General Effect.
NMK band director Bob Medworth said earning a Gold rating and tying for Best Music was "amazing," considering the rain and muddy field the band had to endure.
"It's a credit to the kids that we won music in those conditions," Medworth said.
The Marching Knights will compete in the Cavalcade of Champions at Center Grove High School Saturday.
Northview will take the field at 8:51 p.m., and are scheduled to be the final Class B band in action. Also competing in the event are Zionsville (7:07 p.m.), Whiteland (7:20), Pendleton Heights (7:33), Plainfield (7:46), Bloomington South (7:59), Decatur Central (8:12), Jasper (8:25), and Greenwood (8:38).
Following Saturday's contests, both bands will take part in ISSMA Regional competition.
The ISSMA Semistate competition will take place Oct. 23, followed by state finals Oct. 30, which will be performed at Lucas Oil Stadium.