These four components make up the analog amplifier stage of melody. C209, R213, C211, R215 This is the melody IC. U203 To the speaker at LCD module via CN301.
R227
R222
The Power for analog part of the melody IC. The voltage is 3.3V
The Power for digital part of the melody IC. The voltage is 2.8V. It is from the PMIC(ADP3408, U101)
C221
U205
The circuit diagram of the part of the melody IC. Refer to the page 2 of the complete circuit diagram for detail.