As a user, I would like to be able to listen to my composition at a different volume, so that I can adapt it to whether I want to listen to it at a high volume or at a low volume.
I have implemented this feature in decibels in commit 4d872f8e8c450eef667063043bff55cbae917902. We should probably adapt it so that the users modifies the volume as a percentage rather than as decibels.
Description
As a user, I would like to be able to listen to my composition at a different volume, so that I can adapt it to whether I want to listen to it at a high volume or at a low volume.