Drumpad Machine: Code recommendations and tidying up

I just finished this challenge. I used Jquery and vanilla Javascript because I want to become proficient in them before moving onto other frameworks such as React. While my code works (as in does what it I intend it to), it just looks ugly and unprofessional to me: my biggest beef is with the “display” bit I run after each event, which could be summed up in a function (but I have no idea how to “word” it, sort to speak, because the outcome always depends on the ID of the event target). Any thoughts and recommendations you could make to make it look better? Thanks a lot in advance!
PS: The divs in the button section are there because I use flexbox on them, and it sort of makes sense to group them into groups of three.

Oh, the break! Sorry, a slip!
Yeah. It doesn´t have styling yet, so please ignore that!