How 'bout virtuosity in the pursuit of emotional expression? Ah, that's the ticket! Then again, if I just had to choose one it'd be heart over brain any day.
Billie or Ella? Maria or Renata? Technique or feeling?
I stand back to no one in my admiration for Ella Fitzgerald's technique but all the vocal fireworks make for precious little emotion. Billie Holiday on the other hand makes you feel she's singing just for you.
Technique vs emotion also goes in listening to Renata Tebaldi (superb technique) and Maria Callas who like Lady Day makes you feel she's singing just for you.
David Oistrakh was a violinist who combined flawless technique with raw emotion. Sviatoslav Richter was his counterpart on piano. Their modern day successors are Julia Fischer on violin and Daniil Trifonov on piano.