https://www.musical-u.com/learn/finding-the-tonic-in-major-keys-part-two/
You can think of the tonic as the “home” note in a piece of music. It’s the basis for all the beautiful melodies and harmonies. Without the tonic we would be lost in a mix of seemingly-random notes.
It’s essential that you learn to recognise the tonic by ear. It will help with a plethora of musical skills; singing in tune, improvising, playing by ear and more!
This is part two in our series on Finding the Tonic in Major Keys.