fortissimo
A dynamic marking meaning very loud. Abbreviated as ff.
In Depth
Fortissimo (ff) means very loud, a step above forte and a step below fortississimo. It calls for the performer to project with significant power while maintaining tonal quality — the challenge is producing great volume without sacrificing beauty of sound.
In orchestral music, a tutti fortissimo can be overwhelmingly powerful, with every instrument playing at or near its maximum volume. Composers reserve ff for climactic moments, dramatic outbursts, and passages of great intensity. Brahms, Tchaikovsky, and Mahler all wrote extensively in the fortissimo range, pushing orchestras to their dynamic limits.
Mahler once told his orchestra that if they could still hear the person next to them during a fortissimo passage, they weren't playing loudly enough.