Bill and Earl Bolick — the Blue Sky Boys — sang the gentlest and perhaps the most beautiful brother harmony of the pre-bluegrass era. Where the Monroe Brothers drove their duets hard, the Bolicks kept theirs soft, slow, and devotional: Bill's mandolin and Earl's guitar, two voices in close harmony, and almost nothing else.

They recorded for Victor's Bluebird label beginning in 1936 and stayed with RCA Victor, off and on, into the early 1950s. The repertoire was deliberately old-fashioned even then — sentimental Victorian ballads, mountain tragedies, and hymns, songs like "The Sunny Side of Life" and "The Knoxville Girl" — sung with a purity and restraint that set them apart from the louder, jazzier acts around them.

The Bolicks were proud and particular men. They resisted pressure to modernize, refused to add the fashionable instruments or speed up their tempos, and when they felt the music business no longer had a place for what they did, they simply quit, retiring the act in 1951 rather than compromise it.

That stubbornness preserved something precious. The Blue Sky Boys' records are a window onto the old close-harmony tradition exactly as it stood before bluegrass accelerated and electrified everything around it. Their arrangements and their repertoire became study material for later harmony singers, and bands reaching for an antique, hymn-like sound still turn to the Bolick brothers' singles as the model.

Session details drawn in part from the Bluegrass Discography.