The lady was only using a normal lute. Hence, there were no special mechanisms inside the lute. Long Fan also discovered that the lady only had a spiritual power of about level two as he was able to verify it when he caught her. She was not a threat to him based on her spiritual power. Therefore, he decided to let her stay.
In fact, he was a fan of arts and music as he used to listen to a few plays and classical music when he was in the modern era. However, he had become too obsessed with the scientific studies in this era to continue his hobby. Though most of his subordinates were very good in martial arts, none were good at music. Therefore, he missed listening to music as he had not listened to any in a very long time. He asked, "What music can you play?"
The lady bowed and listed a few famous song titles from this era. Long Fan simply picked one at random. The lady then sat down on a bench and began to play her lute.