Hi David,
Glad you got it sorted. Using arrows to navigate and select is, by design, a single-note process so you can't hear chords in the way you'd like. There are other ways but it depends on your workflow. For example, it's possible to create a selection of, say, a quarter note at the start of a bar. as long as you don't have insertion following playback, pressing the Space bar will only play the selection range and all of the notes within that range are selected. Now, pressing Shift and the plus on the numeric keypad will move the selection range to the next quarter note. To be clear, that command doesn't move the notes but just the selection range. That way you can keep pressing Shift plus and audition each quarter-note section. That is fairly tedious. So, instead, you can set your selection range to one bar and audition greater amounts. If you come across a bar where the second half-note chord needs to be nudged over a bit, quickly make a selection from beat 2, tick 480 or so to beat 4, tick 480 or so and now your chord is sure to be selected, Change the nudge value to a smaller size and use the plus or minus keys on the num pad to nudge. Pro Tools Ultimate offers additional keyboard shortcuts to do things like nudge with greater amounts and extend or halve the selection range.
HTH,
Slau