PGroups in Renardo trigger multiple notes simultaneously on a single beat as a chord

A PGroup is created by wrapping values in parentheses within a pattern: [(0,2,4)] or P[P(0,2,4)]. When a player reaches a PGroup in the sequence, all values in the group fire at the same time, producing a chord. The group occupies a single time slot equal to one dur. This is different from a list of patterns, which plays notes sequentially. PGroups support the same arithmetic as Patterns: (0,2,4) + 7 transposes the chord. The Roman numeral constants I, II, … VII are pre-defined PGroups for common scale chords.

Examples

p1 >> pluck([(0,2,4), (1,3,5)])           # alternating chords
p1 >> pluck([I, IV, V, I])                # chord progression using constants
p1 >> pluck([(0,2,4)] + 7)               # transpose chord up 7 degrees

Assessment

What is the audible difference between p1 >> pluck([0, 2, 4]) and p1 >> pluck([(0, 2, 4)])? How would you write a I–IV–V–I chord progression in Renardo?