The Piano Marvel iPad app sound is controlled by the ringer settings on the iPad. Please check the following.
1. If your iPad has a mute switch, please make sure it is set to the “Ringer On” position.
2. On some iPads, the ringer sound is controlled in the “Control Center” You should be able to access this by swiping up from the bottom on your iPad. Please make sure that they “Mute” setting is set to “off”
3. Please check that the volume on the iPad is turned up. Once these settings have been checked please return to the Piano Marvel app and test the sound.