Around 1910 the “Straube system” had yet to unfold to its full extent, but Straube already worked at a breathless pace on several fronts simultaneously, not without noticeable bumps along the way. One question naturally arising concerns family life on the Dorotheenplatz, which was intensely guarded at the time and only sporadically illumined in the surviving sources. Nevertheless, the dynamics of hearth and home unquestionably constituted another of the many balls Straube was trying to keep in the air. His marriage was seven years old in 1910, Elisabet aged six. The received picture has been one of an essentially sunny home life. But troubles in the marriage were going to arise, whatever their ultimate causes. Karl's overblown schedule demanded a great deal of time away from home, in addition to long stretches of uninterrupted practice, study, score preparation, and correspondence. The interlocking of his many commitments and his stubbornly ambitious nature meant that dedicated vacation time, when it arose at all, was perpetually threatened. Hertha and Elisabet seem often to have traveled independently, leaving Karl with his work or to take his hiking holidays by himself. He had not experienced an ideal domestic environment in Berlin with his unengaged or perhaps even belligerent father, a circumstance that inevitably shaped the expectations he brought to his own home life. Now he was approaching forty, at the top of his game as an organist, thoroughly ensconced in a high-caliber musical culture. It would have been extraordinary if the stress of his professional life had not spilled over into the home.

The trouble began innocently enough. In autumn 1909 Straube studied the Mass in B Minor with his Bach-Verein, mounting on November 15 what he recalled with pride as the “first uncut performance” in Leipzig. He had hired a new alto soloist called Emmi Leisner, a gifted student in Berlin and the daughter of a musical family in Flensburg on the Danish border. At twenty-four, she was twelve years his junior. Soon, Leisner would go on to a distinguished opera career, and in an unpublished biographical essay drafted much after the fact, she pegged Straube's B-minor Mass performance as her professional departure point. He continued to follow her development sympathetically and indeed actively, engaging her again for the May 1911 Leipzig Bachfest as soloist in the St. John Passion.