You can see the octobass from the opening door to the museum after the ticket counter. I didn't know it was there, so when I saw it I am sure I embarrassed my son by exclaiming, "Good Lord, it's an octobass!", running into the exhibiting room, and gushing out all sorts of stuff about the octobass, like how Berlioz wanted to expand the orchestra from 100 to 200 players including a row of octobasses, etc., etc.; even the museum guard came over to listen :-)