As you sing, a collage of images flashes through your mind. Slowly, the images seem to focus, and you can make out the details. You see a well-kept workshop where a wizened elvensmith is in conversation with a younger elf and pointing at the mithril ribcage in his hands.
As you continue to sing, the images refocus once more. You see a young elvensmith laboriously crafting the mithril ribcage from the raw materials laid out before him. As he works, he is chanting some arcane verses that you can't quite make out.
As you continue to sing, the images refocus once more. The elvensmith is inscribing runes of power upon the mithril ribcage. Each rune glows brightly then fades into invisibility.
Your song continues to clarify and focus the images from the past. The ancient elvensmith raises the mithril ribcage and chants an arcane phrase. A flash of light consumes the mithril ribcage. An irridescent aura envelops the mithril ribcage and is absorbed into it. The elvensmith seemingly looks up and gives you a wink and a smile as if he senses your presence.