I feel that what is described as old-timey string band music is devoid of those harmonies.

????????

Except when they sing, of course...

earliest recordings...

Gid Tanner and the Skillet Lickers
Georgia Yellow Hammers
Leake County Revelers
(I'll leave out the Carter Family)

or later...

New Lost City Ramblers
Red Clay Ramblers
Highwoods Stringband

or contemporary...

Foghorn Stringband
Big Medicine
Freighthoppers

A major attraction to old-time music for me is the vocals with harmonies.

-Greg