To sing in a soft, gentle, intimate way, often with a low or soothing voice.
From Dutch 'kroon' or Middle Low German 'kronen,' possibly imitating the sound of crooning itself. The word entered English in the 1700s.
Bing Crosby basically invented the 'crooner' style by being one of the first singers to use microphones—he realized he didn't need to belt like stage singers, so he crooned intimately straight into the mic, revolutionizing popular music forever.
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