This is an approach that has evolved over many years of teaching. I am always trying to improve how I teach and have tried many things. The obvious issue starts with music notation. Those fixed black things on a page that the jazz musicians call the dots, to try and demystify them.
The most basic impulse that we all have is to sing, this is totally different from having a trained voice. If you were given a baby or young child to hold who was crying you would naturally try to bring comfort to the child by singing to it, and rocking it from side to side. You would not be concerned about getting the words right, or being in tune, your concern would be to sooth the child.
Sing-Play is an approach to music learning that develops the ear over the eye, so that the individual immediately can start converting what they hear into the instrument that they are learning ie a digital pattern. This starts from the simple songs that they learnt at kindergarten, to more complex songs, as they master the technical aspects of the specific instrument that they want to play.
My students are often surprised at how many songs they know, or instrumental fragments, (depending on what sort of music they listen to) and are thrilled to be able to Sing-Play.
I get all my students to sing while they play. They notice immediately that if they Sing-Play, their level of digital accuracy immediately improves. So if it is a song they want to play they will learn the words of the song. They will be also able to play the rhythm of the words on their instruments. This gives them the experience of making music from a deep instinctual part of themselves, as they are free from the tyranny of music notation, right notes, right rhythm, correct pitch and all the other rules and regulations. Learning to play all your favorite songs on your instrument means that you always want to play it because you are making music.