How to change note volume?

[DontReadMyName]

Title says it. I'm confused.

I've seen people make cute pictures like Flowey using silent notes, and I'd like to know how to do it.

[wuggie]

Certain instruments only can go so high before they no longer make noise, and other instruments stop making noise when they get too low. The only way to artificially change volume is having multiple notes stacked on top of each other to make them louder.

[RAF2016]

I am trying to make the notes louder or softer and I saw sequences that had teeny tiny bars on the bottom of the notes that make the
notes quiet.

[Arcgon]

Certain instruments only can go so high before they no longer make noise, and other instruments stop making noise when they get too low. The only way to artificially change volume is having multiple notes stacked on top of each other to make them louder.

That's weird. I made and edited a song called 'splitorn melancholy' and I noticed in my most recent edit this morning that the notes I had downloaded and then imported as .mid ended up quiet while new notes added were much louder. Even showed volume bars on them; the old ones were about a quarter white and three quarters black; the new ones have no volume bars.

See: