 In movable do, a given tune is therefore always sol-faed on the same syllables, no matter what key it is in.The solfège syllables used for movable do differ slightly from those used for fixed do, because the English variant of the basic syllables ("ti" instead of "si") is usually used, and chromatically altered syllables are usually included as well.If, at a certain point, the key of a piece modulates, then it is necessary to change the solfège syllables at that point.