1. pieces of music or books?
2. fiction books or factual books?
and 3. (at a slight tangent) the old thing about 'if you stacked up all the sheets of paper in the world, they would reach the sun and back 20 gajillion times...', well...what would reach further: all the sheets of paper in the world stacked up or all the cds and vinyl records in the world stacked up?
all these things occured to me in bed last night.
i expect some truely scientific answers on this. here we go.