In some music, ritards and accelerandi are notated with converging secondary-beam angles in a technique called feathered beaming. In the case of the ritard, the player increases the rhythmic values gradually from the faster values, at the left end, to the slower values, on the right end, as shown below.
To create feathered beaming
To create this form of notation, notate all values as the smallest values (in this case, 64th notes). Then proceed as follows.