Just ran across a great record by the British company Living Era, called "O Brothers" (capitalizing on guess what) containing songs sung by brothers, sisters, and occasionally whole families. Includes the Blue Sky Boys ("TURN YOUR RADIO ON" and others), the Delmores, Stanley Brothers, Monroe Brothers, Crosby Brothers, Carter Family and many more. Stops well before the Everlys. There is something to that close harmony vibe between siblings.

yours, Peter T.

[Some song titles in this thread have been converted to links by a Mudelf.]