Blocks: 120bpm by default for music.
Blocks: 120bpm by default for music.

This fixes bbc/microbit-extras#2140

SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop,jle33/TouchDevelop,SoftwareEngineeringToolDemos/FSE-2012-TouchDevelop,jle33/TouchDevelop