Kapiloh, one of the great sages in Hinduism is Kapiloh. Krishna says, when you think of the Gandharvas and Chitra Rata, think of me. Probably his experience of music was even more ethereal than the way we hear it. That gives you an idea about what Gandharvas might be.
In this series of talks, Swami Sarvapriyananda unfolds the highest truths of Vedanta through the study of the Bhagavad Gita (The Song of God).