The Ramblers were formed by Elwood "Jr." Madeo (name-checked on the cover of "Freak Out!" under the heading "These People Have Contributed Materially In Many Ways To Make Our Music What It Is. Please Do Not Hold It Against Them"); FZ joined a little later; it was his first band. Besides Elwood on guitar, the band consisted of Stuart Congdon: piano / Frank Zappa: drums / other various members. "Jr." Madeo is credited with firing Zappa for "riding the cymbals too much".
From The Real Frank Zappa Book (1989):
By 1956 I was playing in a high school R&B band called the Ramblers. We used to rehearse in the living room of the piano player, Stuart Congdon — his Dad was a preacher. I practiced on pots and pans, held between my knees like bongos. I finally talked my folks into buying a real drum set (secondhand, from a guy up the street, for about fifty dollars). I didn't take delivery on the drum set until a week before our first gig. Since I had never learned to coordinate my hands and feet, I was not very good at keeping time with the kick-drum pedal. The bandleader, Elwood "junior" Madeo, had gotten us a job at a place called the Uptown Hall, at 40th and Mead in the Hillcrcst district of San Diego. Our fee: seven dollars—for the whole band. On the way to the gig, I realized that I had forgotten my drumsticks (my only pair), and we had to drive back across town to get them. Eventually I was fired because they said I played the cymbals too much. It's hard to be a drummer-in-training, because there are very few apartments that are soundproof enough to practice in. (Where do good drummers really come from?)