Transducer apparatus for a labrosone, the labrosone having a labrosone resonant chamber and a labrosone mouthpiece and the transducer apparatus comprising: a labrosone speaker for delivering a sound signal to the labrosone resonant chamber; a labrosone microphone for receiving sound in the labrosone resonant chamber; and an electronic processor which is configured to receive signals from the labrosone microphone and the mouthpiece microphone and which is connected to the labrosone speaker; wherein in use of transducer apparatus: the electronic processor is configured to generate an excitation signal which is delivered as an acoustic excitation signal to the labrosone resonant chamber by the labrosone speaker; and the labrosone microphone is configured to receive a resulting sound from the labrosone resonant chamber; characterised in that: the transducer apparatus comprises a mouthpiece microphone for receiving sound from the labrosone mouthpiece; and in use of the transducer apparatus: the mouthpiece microphone is configured to receive sound from the labrosone mouthpiece; the electronic processor is configured to use the signals from the labrosone microphone and the mouthpiece microphone to determine a desired musical note which a player of the labrosone wishes to play; and the electronic processor is configured to synthesize the desired musical note and output the desired note to one or more of: headphones, a speaker external to the transducer apparatus, computer apparatus and/or a smartphone, whereby the musical note can be played audibly and/or displayed visually to the player. a labrosone speaker for delivering a sound signal to the labrosone resonant chamber; a labrosone microphone for receiving sound in the labrosone resonant chamber; and an electronic processor which is configured to receive signals from the labrosone microphone and the mouthpiece microphone and which is connected to the labrosone speaker; wherein in use of transducer apparatus: the electronic processor is configured to generate an excitation signal which is delivered as an acoustic excitation signal to the labrosone resonant chamber by the labrosone speaker; and the labrosone microphone is configured to receive a resulting sound from the labrosone resonant chamber; characterised in that: the transducer apparatus comprises a mouthpiece microphone for receiving sound from the labrosone mouthpiece; and in use of the transducer apparatus: the mouthpiece microphone is configured to receive sound from the labrosone mouthpiece; the electronic processor is configured to use the signals from the labrosone microphone and the mouthpiece microphone to determine a desired musical note which a player of the labrosone wishes to play; and the electronic processor is configured to synthesize the desired musical note and output the desired note to one or more of: headphones, a speaker external to the transducer apparatus, computer apparatus and/or a smartphone, whereby the musical note can be played audibly and/or displayed visually to the player. the electronic processor is configured to generate an excitation signal which is delivered as an acoustic excitation signal to the labrosone resonant chamber by the labrosone speaker; and the labrosone microphone is configured to receive a resulting sound from the labrosone resonant chamber; characterised in that: the transducer apparatus comprises a mouthpiece microphone for receiving sound from the labrosone mouthpiece; and in use of the transducer apparatus: the mouthpiece microphone is configured to receive sound from the labrosone mouthpiece; the electronic processor is configured to use the signals from the labrosone microphone and the mouthpiece microphone to determine a desired musical note which a player of the labrosone wishes to play; and the electronic processor is configured to synthesize the desired musical note and output the desired note to one or more of: headphones, a speaker external to the transducer apparatus, computer apparatus and/or a smartphone, whereby the musical note can be played audibly and/or displayed visually to the player. the mouthpiece microphone is configured to receive sound from the labrosone mouthpiece; the electronic processor is configured to use the signals from the labrosone microphone and the mouthpiece microphone to determine a desired musical note which a player of the labrosone wishes to play; and the electronic processor is configured to synthesize the desired musical note and output the desired note to one or more of: headphones, a speaker external to the transducer apparatus, computer apparatus and/or a smartphone, whereby the musical note can be played audibly and/or displayed visually to the player.