Penny L. Carmack found Solfeg.io:

• Moderately reduces teacher workload“I find well produced lessons that have a definite and logical progression.”
• Slightly increases student collaboration“Students wanted to perform together”
• Moderately improves teaching efficiency“The lessons help streamline information to the students.”
• Slightly improves behaviour or wellbeing“Some students are more engaged.”
• Moderately builds student knowledge“Movement activities have helped students remember music terminology.”