Check out this cool trick by saxophonist and hobbyist, David Pope. He put out a video of a piece of paper floating in mid-air inside the bell of a saxophone. It looked pretty cool as he played the saxophone while the paper stayed levitated.
The science behind the levitation of the piece of paper is simple. The saxophone will keep the piece of paper afloat due to the sound vibrations in the space within the bell of the saxophone and not because of the air flowing through the bell.