• Now the speaker looks back on the powerful music he heard in that vision.
• He can describe it to us, but he can't really get back to experiencing that intense feeling. And yet he's longing for that experience, for the sense of wonder that disappeared with that vision.
• The speaker wants to "revive" the music, to bring it back to life. If he could tap into the power of that vision, he imagines that it would inspire him, and allow him to create amazing things himself.