sentences:  The new FM-X synth engine in the Yamaha Montage is based on features from the FS1R.The FS1R uses the "formant sequence", this being a series (128 or 512) of "frames" that define the level and frequency of each of up to eight 'voiced' (pitched) and eight 'unvoiced' (un-pitched) formant generators over time.The number of frames limits the typical length of a sequence to a few seconds, though this length and pitch can be varied in real-time with few or no artefacts.