We drew the harp from the treasure room as one of the two treasures while the dragon slept. It said the next time you are in the treasure room, draw two dragon cards.
I get this, because the harp is noisy, so you have two chances to wake the dragon instead of one. However, what if you don't wake the dragon? You now have two cards that tell you to draw two treasures each. Drawing four treasures in one turn doesn't seem right just because you have a noisy instrument. Which is how we play it. But technically, there is no restriction on the harp's card to say only two treasures, and the instruction book does not restric to two treasures either, it simply says to follow the dragon card.
Like I said, I believe you should only still draw two treasures, but is that what you are supposed to do? Is four treasures an added bonus of the harp for taking a riskier chance? Maybe something for the next FAQ update.