The Brady kids fucked up and can't afford to purchase the silver platter (it's all Jan's fault, duh) they'd picked out for Carol and Mike's anniversary. So they go down to the Pete Sterne Amateur Hour and perform "Keep On" (dig the jumpsuits) on live television in the hopes of winning a fat check. Their band's name is The Silver Platters. Get it? Well, they lose. (Sad face.) But Carol and Mike and Alice see their performance and buy the platter themselves. Heartwarming. The above clip is their rehearsal number "It's a Sunshine Day."
Can't you dig the sunshine? Well? Can't you? I can, sure, but the fucking humidity gets me every time.