Sound recording copyright symbol

The sound recording copyright symbol or phonogram symbol, ℗ (letter P in a circle), is the copyright symbol used to provide notice of copyright or neighboring rights in a sound recording (phonogram) embodied in a phonorecord (LPs, audiotapes, cassette tapes, compact discs, etc.). It was first introduced in the Rome Convention for the Protection of Performers, Producers of Phonograms and Broadcasting Organisations in 1961.

Source: Wikipedia — Sound recording copyright symbol (CC BY-SA 4.0)