Suppose that there was a culture that naturally developed a musical system/tradition that us western Earth people would call a "loose" interpretation of dodecaphony or 12-tone music (https://en.wikipedia.org/wiki/Twelve-tone_technique.)
What I mean by "loose" is that this culture just thinks of a tone row's matrix (http://www.carolingianrealm.info/Music.php?MusicID=29) as 2-dimensional scale, and don't impose further onto it. For example, they wouldn't have a rule about not playing the same note until all other 11 have been played.
Now that I've defined how their music works, what would their 'go-to' instrument look like?
For example, I was thinking maybe something like the autoharp (https://en.wikipedia.org/wiki/Autoharp), but instead of the buttons being used for chords, you could have a button for each note in the matrix, with some way to configure it for different matrices?