This Bach invention is very cool because one part is being played by Fleck on the banjo and the second part is Evelyn Glennie on the marimba. If it were being performed on piano, I would guess that Fleck is performing the right hand and Glennie is playing the left hand. The song is definitly in a simple meter, either two-four or four-four. The beginning is the marimba playing do on the down beat and the banjo soming in on the weak beat with sol-do-me-re-sol-re-fa-me-sol-re-sol. The first measure of the marimba part plays start eighth notes until the me-sol-re-sol in the banjo part because at those notes to banjo switches to eighths and the marimba plays the moving sixteenth notes. As in all inventions the melody is traded between parts throughout the song. The piece seems to be closed because the A section ends with ti-do. The song is rounded because the A section repeats at the end. The form is hard to explain though because the piece is so continuous. It begins in a minor key and then there is sort of an extension to the second phrase of the A section which modulates to a major key. After this major section, there is an obvious modulation back to the minor but with a different melody, signifying a new section. In this portion the marimba is stronger in playing the melody. The last portion before the end is the original A section with some variations. The end of the song has a very obvious i64-V-i and a perfect authentic cadence.
I enjoy invention because they never seem to stop or break until the very end. One of the parts is always playing and it can even be confusing at times as to when sections begin and end. The marimba has a great sound because it can be stong and stable on the accompanying eighth notes or light and bouncy on the moving parts.