Question

His daughter watched him intently, and lovingly, as his fingers made the strings sing a song. Which object or concept is personified here?

Answer 1

Strings is the main object personified here.   Strings are described as singing a song which is a human activity.   Author has used the literary device personification in order to tell the level of music which was coming out of the strings.   Personification compares objects to human beings and treat them as someone having feelings and emotions.