So, can we get by with a single chord?
Music Times lists six great songs with only one chord:
Chain of Fools by Aretha Franklin (1967)
Coconut by Harry Nilsson (1971)
Madeleine-Mary by Bonnie ‘Prince’ Billy (1999)
Run Through the Jungle by Creedence Clearwater Revival (1970)
Tomorrow Never Knows by The Beatles (1966)
As another example, here’s Ohm by Yo La Tengo (2013) …
And here’s an example of my own. It’s called Five More because it’s in 5/4 time …
Instruments used on Five More:
Bass: VB-Rowdy from ujam
Drums: VD-Phat from ujam
Voice: Forgotten Voices – Terrie from 8Dio
Electric Guitar: VG-Iron from ujam
The reality is that, while a single chord can work, it’s a huge constraint and an unnecessary one.