
noun
Definition: guess, belief
Antonyms: fact, knowledge, proof, reality
(1) The concept, proposed by Rameau, that chords of the 9th and 11th, among others, arise from a 7th chord by placing a ‘supposed’ bass one or two 3rds below the Fundamental bass (e.g. in the chord f-a-c′-e′-g′-b′ the fundamental bass is c′ and the ‘supposed’ bass is f).
(2) The imagining of a different clef sign, or the existing one differently placed, in a piece of music, thus enabling a player to transpose music that he is playing.