Why do people insist on playing quiet chamber instruments in an auditorium? Pick a louder instrument which can fill a big room - there are lots. That said, a dedicated microphone can give excellent results and then one can add compression, harmonies, and any number of wonderful effects which come with the conversion to electricity and the digital world. Singers can also benefit from these effects. In fact it's likely that they'd catch the attention of a few "youngsters" if they did that.