Case in point.

Last week I was asked to sing a particular song for which my accompaniment is in a modal tuning, runs and arpeggios with not a single chord reading it's melodic head. Fingers doing what Mike Harding calls "little white maggots with St Vitus Dance."

However, it wasn't a concert but a singaround in a noisy pub.

Guitar tuned to concert. Out came the plectrum. Get thrashing......

Horses for courses.

This thread could of course be about the versatility of the guitar and make the same arguments.