Have you ever heard someone sing with a surprising quality of presence and clarity? When the voice cuts through like a diamond, and you might experience goose bumps? That is how you can recognize that a greater power is with him/her singing, or just playing any instrument: The Holy Spirit.
Likewise, when you hear a discord and noise, or falsely singing, there is no presence. I believe the same applies to how we talk. Our own spirit merges with the Holy Spirit and thus we indeed become an instrument, depending on the occasion and content. It's all about the sound, that we can create a sense of harmony with. And this is also the wisdom embedded in sacred chanting, which is why this is a must for spiritual practices.
Start by acknowledging the great music around you. Music, as in actual instruments, but also the various sounds of nature, and of the city, that can form a rhythm and backdrop to your life. Listen to this "stream"... and find your own!
"Everybody lies in the gutter, but some of us see the stars." (Oscar Wilde)