This is a fantastically challenging piece, requiring not only a constant sharp focus on the technical demands, but also a refined flexibility of tone and timbre.
By the way, The study done by Mehrabian in 1979 on communication channels indicates that in face-to-face conversation, 55% of meaning is communicated via NVC, 7% via the verbal language (words) and 38% via the paralinguistics (Tone, timbre, speed of speaking, etc) and ALL THREE areas have to be taken into consideration when assessing communication.