Abstract: A humidifier and digital hygrometer/thermometer device for use with a stringed, musical instrument having a sound hole includes: (a) a polyvinyl acetate sponge adapted to hold a specified volume of water, (b) a container having an opening adapted to accommodate the sponge and fit within the instrument's sound hole, (c) a case adapted to rest on the instrument's strings , (d) a relative humidity measuring means, (e) a temperature measuring means, (f) a digital display means, (g) a processing element adapted to process the data from the humidity and temperature measuring means and cause the digital display means to display appropriate humidity and temperature measurements, data and further adapted to fit within the case, (h) an adapter affixed to the case and adapted to detachably attach the container to the case.