Carole Lombard and Marlene Dietrich, shown with Paramount stablemate Cary Grant at the Venice Pier party Lombard hosted in June 1935, had a, shall we say, unusual relationship.
Professionally friendly, one biographer states that in 1934 the bisexual Marlene made a pass at Carole (https://carole-and-co.livejournal.com/346936.html), only to discover that Lombard was on "team penis," to borrow the term Christy Plunkett (Anna Faris) once used on an episode of "Mom." Dietrich's daughter Maria Riva writes that her mother had an up-and-down relationship with Carole, occasionally close, more often catty (https://carole-and-co.livejournal.com/414055.html).
However, Riva doesn't write anything about how her mother viewed Lombard's invasion of Marlene's turf -- singing.
On the surface, that doesn't appear to be a fair fight. Dietrich, a trained musician from her youth (and shown in a 1952 recording session for Columbia) performed to audiences for decades. Carole never officially cut a record and was dubbed throughout her film career, save for the 1937 "Swing High, Swing Low," where director Mitchell Leisen cajoled her into warbling. (She might've used a less charitable phrase.)
But in 1935, Dietrich sang "If It Isn't Pain (Then It Isn't Love)," from veteran composers Leo Robin and Ralph Rainger, for her final collaboration with Josef von Sternberg, "The Devil Is A Woman." The film was set in Spain, and there's a definite flamenco feel to it:
However, it was excised from the final release, and only the soundtrack version survives.
In late 1936, Paramount handed it to Leisen and Lombard for "Swing High, Swing Low," although the emphasis on the sheet music was changed to the less masochistic "Then It Isn't Love":
Here's Carole's version:
She holds her own, though it's more a talk-sing performance than actual singing.
Facebook friend David Noh, who refers to Dietrich's version as an "SM anthem," actually prefers Lombard's version.
Is it better? I don't know. But it shows that had Carole possessed a bit more self-confidence about her vocal ability (she enjoyed singing at parties), she might have pulled it off.