Guitar, bass, drums. The standard rock trio. The reason it works (keeps working again and again) is that each instrument occupies a distinct part of the sonic spectrum: The guitar is high, bass is low, and drums provide structure. Importantly, a trio doesn’t need to be those instruments, but it does have to respect that balance of registers and roles. Look at jazz: Same dynamic, you just trade the guitar for a piano or saxophone. Or how about a string trio—violin, viola, cello—same, same, same. You could have a trio of glockenspiel, harpsichord, and tuba, and as long as the roles and registers are the same, there’s no reason it shouldn’t work.
This principle of balance and tone is even more true of cocktails, and the reason we’re talking about it today is because this is how I think abo