Recently I was working on a challenging transition with my TTBB group. They had to go from a unison G to a 2nd-inversion Eb ma7 chord. The crunchy half-step between B1 and T2 was tricky.
The solution? Rehearse with just one part at a time. Without the B1s, the chord rang as a simple E-flat major triad. Without the T2s, a G minor.
Five or ten drills of each of those, and each part knew what to listen for to lock their chord. When it came together, it suddenly rang true.
Finding underlying simple structures, like major triads, and isolating them in rehearsal is a great way to empower your singers to sing more accurately by listening to what’s happening around them.