study showed that years of musical training leave the brains of musicians better attuned to the emotional content, like anger, of vocal sounds

The concept of 'anger' for instance is firstly a higher cortical mapping of a 'feeling'. As higher cortical skills are enhanced, the 'spectrum' of subtle 'shades', ;hues' of a basic emotion expands. That cognitive enhancement, also achieved by other than music such as poetry, leads to more sensitive recognition of emotions. Perhaps?

"Perhaps?"
DOES!