It’s got three knobs, no patches and only makes one noise, but Cellofan’s cello synthesis is as good or better than most commercial options’, and it’s lightweight and free. You can control the attack and release of the cello, then use the Slide knob to add glide. Cellofan is polyphonic, although it sounds best when it’s only playing one or two notes simultaneously. The only major downsides to the instrument are its lack of velocity control and that it’s only available as a Windows VST instrument. You can download a free copy of Cellofan from Soundkeys.