Roland RP30 88-Key Digital Piano (Dark Rosewood) - Manual (Page 14)

Press and hold the [FUNCTION] button, then press one of the
[TEMPO] keys to set the desired tempo, over a range of 30–280.
Tempo
14
The transpose function allows the overall pitch of the instrument to be
transposed up or down in semitone steps, over a range of -6–+5.
Press and hold the [FUNCTION] button, then press one of the
[Transpose] keys to set the transpose value.
For example, set the transpose value to -5, you will hear “G” pitch
when playing the “C” keys.
Note:
Press and hold the [FUNCTION] button, then press the [Transpose +1]
and [Transpose -1] keys at the same time to restore the default setting
“0.”
Transpose
Parameter
+1
-1
Description
To raise the overall pitch by 1 semitone.
To lower the overall pitch by 1 semitone.