After connecting the sensors, the Bamboo should indicate “await signal” because it’s exploring the range of all possible resistances. When the device finds the exact working point, where the plant is reacting, it starts playing with the message “music playing”.
When the message “no signal” appears, it means that the electrical signal is not strong enough to be detected. At this point you need to moisten the leaf again or you could try to unplug and plug the sensor so that the device can scan the resistance range again.

Also we suggest watching the very intuitive tutorial for images that you find on the homepage.