https://www.musical-u.com/learn/an-easy-approach-to-playing-by-ear/
You may already have a few good reasons for training your ears, or maybe you’ve just heard that “good musicians need to have a pair of good ears”. Ear training is about “musifying” yourself: really tuning your ears and brain for music.
https://www.musical-u.com/learn/an-easy-approach-to-playing-by-ear/