Those ribbons

[dll927]

Several times, while watching videos that show pipes inside of chambers, I've seen ranks with what seem to be ribbons tied around each pipe. This can't do much to affect the sound, so what is the reason? Just doesn't seem like much of a place for decoration.

[FinnViking]

Most likely they support the pipes, i.e. prevent them from falling.

[Krummhorn]

FinnViking is correct ... used primarily on reed pipes, although can be on other ranks, too. The reed pipes flare more at the top, making them a bit more top heavy than a straight or narrow pipe. Those have no effect on the sound of the pipe.

[AllanP]

Both of the answers above are correct. On my organ the longer metal flue pipes are all tied about 1/3 of the way from the top with twill ties from the 8' pipe for about two octaves. The reeds and the larger wood pipes have pipe hooks that are directly connected to the support structure (usually called rack boards). The strings being slender pipes tend to have more pipes tied than diapasons which are of larger diameter and made of thicker metal than strings.

The trumpets all have pipe hooks rather than twill ties.