It is a well-known fact that music can be an amazing tool for conveying emotion and triggering memories. What if you decide to combine the two, and create songs that represent your daily thoughts and activities?
Music-of-Thoughts is a wearable device that records your heartbeat, steps, distance you've traveled, and if possible, even the amount of certain hormones in your blood - basically similar to fitbit or Apple Watch, but it will convert these data into a song. It will be able to keep track of your activities and emotions and produce songs with varying rhythms and chords. (For example when you were running that part of the song will be faster and when you were feeling down the song would be in minor chords) The device would also have a certain input system that would allow you to manually highlight certain parts of the experience (ex: when you were running and saw an UFO you'd press the button on the device and later on the song would have a loud 'ding' at that spot to convey the significance of the moment) After the device has finished recording songs, you'll be able to listen to them and revisit your past memories - basically 'listen' to your memories, thoughts and emotions.