He nods to her, and continues to play.

This variation emphasizes centering and calm through creating stillness within. As his fingers move deftly over the strings, a faint blue glow shimmers from time to time at points of particular resonance.

Continuing to pour spiritual energy into the music for an extended length of time would become difficult very quickly for some people. For someone whose cultivation and golden core is as powerful as Lan Wangji's, it would take hours before tiredness would become a factor.