Gradual change of tempo
The last type of tempo change is one where the tempo changes gradually over a period of time. It’s easier to slow down than speed up. A rallentando is basically a relaxing of energy, and singers have a natural tendency to slow down. On the other hand, an accelerando is more challenging since great energy is needed to prompt singers to get faster.

Accelerando
To show an accelerando, your beat patterns need to get faster and smaller. This is because they travel through space in less time.