Lyrically, Marvin Gaye's "What's Goin' On" held up an effective mirror to society, illustrating clashes between generations and asking for peaceful resolutions.
Instrumentally, the Carolbeth True Trio shows how well the tune holds up melodically. Even without vocals, the tune succeeds rhythmically with just piano, bass, and drums.
As I keep saying, sometimes, a rhythm section is all you need.
