What is a "Per Program" License?

This is similar to a blanket license.

A "per program" license is similar to the blanket license in that it authorizes a radio or television broadcaster to use all music in the repertory of the PRO it obtains the license from. However, the fee varies depending on the specific radio or television programs that contain that music, requiring that the user keep track of all music used. Also, the user must be certain to obtain rights for all the music used in programs not covered by the license.