Feature Request: Ability to change volume via keyboard in finer steps

Feature Request: Sorry I don't know which category this belongs into so I chose Ayatana as the general UI component group because this is in my opinion an UI feature.

Behavior now:
Hitting the volume up or down keys on the keyboard changes the volume by a large amount. That is totally ok behavior as per default because you usually want to be able to make large changes to volume quickly. However it is often not sufficient when listening to music when you want to adjust volume slightly depending on the song.

Desired behavior:
Apple have this very handy feature available in Mac OS, even though it's not well known, and it works like this: Apple's visual feedback of volume is divded into 16 bubbles. When you hit VolumeUp / Down once you change volume by an entire bubble, which is about equal to how much it is in Ubuntu right now. When you however press Alt + Shift + VolumeUp / Down you change volume by only a quater of a bubble. This essentially increases the achievable resolution in volume from 16 to 64 steps, directly reachable through the keyboard, which is very desireable.

I'd love to see this feature in Ubuntu! Thanks for your consideration!