This work proposes a new type of portable piano based on a gridless flexible intelligent pressure-sensing system, deep neural networks (DNNs), and hardware circuits. First, a gridless flexible sensor with the same shape and size of a traditional piano key is fabricated using carbon black (CB)-doped polydimethylsiloxane (PDMS). Second, with the help of DNN, the gridless flexible sensor replaces the traditional piano key to collect the pressing pressure and location information in real time. Finally, the collected information is used to drive a speaker to make the corresponding piano sound, mimicking the accurate response of a traditional piano key when pressed with the same location and magnitude. In terms of material innovation, a multilayer packaging scheme for the sensor is developed so that the resistance change rate of the sample after 21 days was less than 2%, and the average coefficient of variation (CV) was close to 1%, which greatly improves the long-term stability. In terms of mechanism innovation, the DNN accurately predicts the magnitude and location of pressure, with an average localization error of less than 3% and an average pressure prediction error of less than 1%, so that the sound of the target frequency can be precisely stimulated.