When asked for a request during a wedding reception, it suggests that the musicians are valued, especially during warm informal gathering. To an artist, it is a transported delight.

A performer has ready materials for unwelcome instances and to allude genuine concern for those around who want to be cheered. 

A live music band makes it easy for immediate responses. Even a guest who wants to be involved is welcome and the musicians are happy to improvise with a song or two letting the guest take the honors. A guest is always welcome.