I retract! I repent in dust and ashes. Ok wait a minute… forget the dust part. I’ve seen too much of it lately.  Awhile ago i wrote about the fact that dust is not the enemy to pianos.  Rather, it is humidity fluctuation.  Well… i’m going to modify my statement.  I’ll retract a portion of that.  GENERALLY… dust is not an issue.  EXCEPT when it blocks the keys.  “Dust blocks the keys?” you ask. Yep… seen it… photographed it.  I was asked to work on an older grand piano.  And well… these were not only dust BUNNIES… they were dust… mmmm LLAMAS! Big whopping pieces of dust laminated by years of uncleanliness. (Ewwww right?)  Anywhooo… the problem comes under the keys where there are felt punchings.  Y’see it’s the felt underneath that stops the key from travelling.  Each key is set to a certain depth.  Now what happens when you place a dust…mmmm Llama on top of that felt piece? Exackly… you have a shallow key dip.  Such was the case with the piano photographed.  A couple of swipes with the vacuum and VOILA! At least that portion of piano irregularities was taken care of.  Good as new? Not quite… it was still 100 year old piano… more like… on to the next challenge.