Go to Dragon Roost Island, and go inside and out onto the outer balcony (The last door I think), go right along the wooden balcony and swing across the gap using the grapple hook, go up and talk to Medli, and play the Earth God's Lyric. (Make sure you take a picture of Kogoli (The bird guy on the right on the wooden balcony), because he leaves afterwards, and you can't get his figurine if that happens)

Bat178's answer is good for the harp, but the person with the fiddle is Makar (reason you went into 2nd dungeon). To find him, go to the forest island (what is the name of it?) and use the grappling hook to swing into the waterfall (there is music coming out of it), and then you have to play the wind gods aria for him
Note: You have to finish the ice island to get Makar to appear

You go to forest haven and look up by the water fall and you can swing with your grapple hook and you will find makar and go to dragonroost andgo to all the rooms and you will see medli playing her harp