This goal has the following fine print specified by d20diceman:

Tracking how long I've spent practising piano.
Until 19/09/2023, this tracked all piano learning.

Music practice is now tracked in 4 goals:
Practising piano using Synthesia: https://www.beeminder.com/d20diceman/synthesia
Traditional piano practice (including lessons and recitals) on this goal
Learning music theory: https://www.beeminder.com/d20diceman/theory
Practising drums: https://www.beeminder.com/d20diceman/drum

My target is to do 4hrs music practice per week, with a minimum of 30 minutes from each category.

Data entered into these four goals is automatically duplicated to the MetaBee Of Dexterity at https://www.beeminder.com/d20diceman/dex