Well before the radio cantatas, Straube had consolidated a position of multilayered influence surely unprecedented in the St. Thomas cantorate. Many factors had contributed to the potency of that influence, nothing more consistently than his promotion of J. S. Bach's music in countless performances that bore his subjective stamp. He had used his positions to cultivate his forebear's art with an intensity not seen since Bach's own time. The result was that, whether concerning Bruno Walter's questions about cuts in the first Brandenburg Concerto or Karl Böhm's deliberations over tempi in the St. Matthew Passion, Straube, for many, had become the go-to authority for all things Bach. As first the tours and then the radio exposed the Thomanerchor to expanding audiences, and as the Thomaskantor grew ever more at one with Leipzig's cultural identity, public perception began to frame him as something beyond a supreme Bach interpreter. Particularly among his allies he was becoming a Bach avatar.

“Bach is Bach and Straube is his prophet!” was the extravagant closing flourish in his former pupil Richard Engländer's review of the 1930 Bachfest. More frequently now, writers would find variations on this sentiment. That same year brought Julius Levin's Bach biography, a 200-plus-page read that cadenced, “Among the representatives of Bach's spirit, as far as concerns the embodiment of his thoughts, stands in Germany first and foremost Bach's successor … Karl Straube.” Anton Kippenberg would best distill this position in 1935, when he related an ecstatic dream in which Bach himself appeared by night to an intimate company in the Kippenberg home, Straube among them. The resurrected Bach “greeted his twelfth [sic] successor like an old acquaintance with a firm handshake. Now there is nothing remarkable about this, because of course the cognatio spiritualis unites the Thomaskantoren. They constitute an unending chain—le roi ne meurt. And the kings all know each other.” As the popes enjoyed a bond through Peter's spirit, so Straube re-presented Bach's spirit, wielded to help the German republic reclaim its place in the family of nations via the supposed universality of its music. Through the lens of what he believed passionately to be his mission, this was a cognatio spiritualis placed squarely in the service of cultural policy.