Songfacts®:

• This is the song the Brady Bunch kids performed on The Pete Sterne Amateur Hour in the 1972 Brady Bunch episode "Amateur Nite." Performing as The Silver Platters, they went on the show to win the $100 prize so they could buy (you guessed it) a silver platter as an anniversary gift for their parents. They end up losing, but their parents see them on the show, which is an even better present.
• The Brady Bunch ventured into music in 1970 by releasing a Christmas album called Merry Christmas From The Brady Bunch. The "Amateur Nite" episode showcased their singing and included another performance as well: another original song called "It's A Sunshine Day." They released four albums and even toured, playing state fairs and the like, sometimes as an opening act.
  
  For the most part, they did their own singing, although "Keep On" sounds pretty slick and because all the voices are singing at once, it's possible they got some professional help. On "It's A Sunshine Day" four of the kids do solos and it's clearly their voices.
  
  The final season of the show, in 1973, opens with another musical episode: "Adios, Johnny Bravo," where they sing two more songs: "You've Got To Be In Love (To Love a Love Song)" and "Good Time Music." In 1976, the Bunch returned to TV with their own variety show, The Brady Bunch Hour, that lasted one season. They closed every episode by singing "United We Stand."
• The songs performed on the show were very cheerful and generic, like the show itself. "Keep On" is about riding around in a "makeshift Model TA," having fun. Our guess is that a "makeshift Model TA" is a model Trans-Am they're playing with - after all, at least four of the Brady kids were too young to drive.
• "Keep On" was written by the songwriters Jackie Mills and Thomas Jenkins. Mills, also a drummer, co-wrote two songs that appeared on the 1972 Meet the Brady Bunch album but weren't used on the show: "We'll Always Be Friends" and "I Believe in You." Jenkins later worked on the music for The Brady Bunch Movie in 1995.