The Latin capital letter "P" in a circle actually represents the copyright symbol used in the music industry. This symbol indicates a melody, composition, song, or other work which is protected by copyright. The letter "P" is used in the symbol for a reason; it refers to the English word "phonogram."

Usually, next to the Sound Recording Copyright symbol you can also see the year of the work's release and the owner's identifier. The unfilled circle with a "P" belongs to [BLOCK:letterlike-symbols].