I think each track should have a volume + and - button, so that if the snare is not loud enough or is too loud, you can fix it.

I don't think this program should try to become FL Studio, but that plus the ability to HOLD a note and there would be a lot more possible songs you could make. Inability to HOLD a note and inability to set an instrument louder or quieter is very frustrating.

It should be possible to have especially bass notes hold.

As a dad, who would like my kids to be able to use this, I also think that the copy and paste features should be made into regular buttons so you don't have to RIGHT click, or in the case of a macbook with a trackpad,  Control and tap on trackpad.    RIght clicking is not a very discoverable or friendly feature for this friendly app.

A much friendlier set of icons would have been an UP Arrow pointing TO a clipboard and a DOWN arrow point from the clipboard to your grid.

Thank you for your feedback, this will be useful for future versions 🙂

You can change the volume of an instrument by moving the slider: