Consider the character of spiritual experience and what it has in common with the experience of music.
Spiritual experiences often include a sense of immersion in the divine. Because we are likewise immersed in sound, music is the best art for evoking the divine.
Spiritual experience is deeply emotional. The experience of emotions is also one of immersion and duration. They color our perceptions of everything and everyone around us. Music, with its ebb and flow, its rhythms and evocative harmonies, is emotive because it emulates and expresses the immersion and the ebb and flow of emotion. Music, an expression of our humanity, is rooted in emotions.
Another feature of spiritual experience is that words cannot adequately express it (is ineffable.) The words that do come can only provide an opening for the same divine spark to awaken in the listener. Music, being an evocative non-verbal language can also provide an opening for the divine spark to awaken. Music is an excellent vehicle for expressing and evoking what words alone cannot.
Probably the most universal religious experience is that of awe when faced with natural beauty. (“awe precedes faith…” Abraham Heschel) Beautiful music, just like the beauty of nature, can open us to the divine. So one way to answer the question of how music opens our hearts to God might be to look at the connection from natural beauty to awe to faith and ask what it is about music that helps us make that same connection.
Those who have spiritual experiences seek to make sense of those experiences. Religions provide a stories – a narrative context that helps us story (make sense of) our experiences. Music is also narrative. It takes us from A to B and leaves us transformed by the journey. It gives expression to our shared story – our common humanity. Religions provide a social context – a validating context of like-minded seekers who share and seek to live out fully a common story. Music is also communal. Musical ensembles are united in common purpose, immersed in the moment together for the sake of their art. Performers and audiences share a bond that goes beyond words and is rooted in our shared humanity. Music, in its narrative structure and communal nature, is a apt vehicle for creating and strengthening religious communities by expressing and evoking the very realities that bind them.