This is from justinkim/PWM_Tone_Library modified for six octaves.

Fork of PWM_Tone_Library by justin kim

Revision:
2:1d3262096227
Parent:
0:d06af372d384
--- a/pwm_tone.cpp	Fri Jul 24 05:01:45 2015 +0000
+++ b/pwm_tone.cpp	Tue Apr 18 15:57:38 2017 +0000
@@ -28,7 +28,7 @@
 /**
    * @brief     Auto tunes Function
    * @param  name : Choose the PwmOut
-                    period : this param is tune value. (C_3...B_5)
+                    period : this param is tune value. (C_1...B_6)
                     beat : this param is beat value. (1..16) 1 means 1/16 beat
    * @retval    None
    */