Feed FM is a service that provides popular music for hold music, aiming to make it less boring. They offer an API and integrate with Twilio to allow developers to easily add music to their apps and websites. Feed FM's Music as a Service philosophy aims to improve customer experience through music. A demo shows how to integrate Feed FM's database into a Twilio app using the TwiML markup language, allowing developers to create a hold queue that plays requested music instead of default Twilio hold music. The integration involves requesting music from Feed FM's API and generating a TwiML document to instruct Twilio to play the song. A node script is used to request music, generate a TwiML document, and cache client IDs for authentication purposes. The final implementation sticks together all the pieces and includes a server-side cache to map caller phone numbers to client IDs.