https://www.musical-u.com/learn/play-melodies-by-ear-using-intervals-a-roadmap/
Two of the most common questions musicians have about ear training are: “how can I play by ear?” and “what’s the point of intervals?”. In this article I’m going to share a step-by-step approach you can use to learn intervals and put them to practical use to play melodies (tunes) by ear. https://www.musical-u.com/learn/play-melodies-by-ear-using-intervals-a-roadmap/