On 24 March 1949, Helmut and Erwin Kremers were born in Mönchengladbach. They went on to become German internationals and the first twins to play in the Bundesliga.
Both of them started their careers as youth players with their hometown team, Borussia Mönchengladbach, then joined the club as professionals in 1967. They continued as teammates at other clubs. moving to Kickers Offenbach in 1969, then to Schalke in 1971. Erwin, a striker, retired in 1979, but Helmut, a full back, played for three more years, remaining with Schalke until 1980 then spending time with Rot-Weiss Essen (1980-81), the Calgary Boomers (1981) and the Memphis Americans (1981-82).
Virtually inseparable at the club level, the brothers played together only twice on the international stage. Erwin made 15 appearances for West Germany between 1972 and 1974, winning the 1972 European Championship. Helmut received a later a call-up and got fewer caps--8 between 1973 and 1975--but was part of West Germany's World Cup-winning side in 1974.
Despite their footballing accomplishments, they are widely remembered for their 1974 record release, "Das Mädchen Meiner Träume," which translates to "The Girl of My Dreams." The B-side was apparently titled "Mo-Di-Mi-Do," which, I assume, needs no translation.