MS4 - change playback "voice"

Hi Peoples - plz - in MS3 I was able to edit the playback vioce (e.g. I could change in SATB (say) Tenor to "Harp" to emphasise precise entry timing... or to cello to emphasise sustain.... ) but with MS4 the only thing shown availbe is "Musescore Basic" which I do not seem to be able to access... I have tried to install Muse Sounds but the download will not install - so please, could someone kindly direct me to achieve "voice change" options?
Thank you.