"In music, the word dynamics refers to the volume of the sound. The renaissance composer Giovanni Gabrieli was one of the first to indicate dynamics in music notation.
The two basic dynamic indications in music are piano, meaning "softly" or "quietly", usually abbreviated as p; and forte, meaning "loudly" or "strong", usually abbreviated as f. More subtle degrees of loudness or softness are indicated by mp, standing for mezzo-piano, and meaning "half-quiet"; and mf, mezzo-forte, "half loud".
Beyond f and p, there is ff, standing for "fortissimo", and meaning "very loudly"; and pp, standing for "pianissimo", and meaning "very quietly". To indicate even more extreme degrees of intensity, more ps or fs are added as required. fff (fortississimo) and ppp (pianississimo) are found in sheet music quite frequently, but more than three fs or ps is quite rare. It is sometimes said that pppp stands for pianissississimo, but such words are very rarely used either in speech or writing, even when present in a score."