My favorite is Excercise 33, Slow Dance. The title is suggestive, plus it's in 6/4 time, so there are enough cues to make the job of teasing out the music easier.
But the key, I think, makes it special, makes the notes ring like a cosmic waltz.
And the word Mikrokosmos may be interpreted as a series of pieces in many different styles, representing a small world. Or it may be interpreted as "world of the little ones, the children".I like this. I really, really like this variegated cycle of mini piano pieces. In each page I feel like a child for whom everything is a discovery.
—From the Foreward by Peter Bartók, son of Béla Bartók
Here's another exercise I enjoyed from the first book.
On to the next one—