In many respects, the '50s and early '60s represent the same kind of classic "golden age" in bluegrass music as they do in rock 'n' roll. Bluegrass record collectors don't seek out the early releases of Bill Monroe, Flatt and Scruggs or the Stanley Brothers just because the records are old or rare. There is a quality in early bluegrass music, a more forceful link to the folk past heard especially in the heartfelt vocal styles, that seems irretrievable even by the most devotedly traditional acts of today.

Some of bluegrass' most memorable recordings were those made by the earliest versions of Lester Flatt and Earl Scruggs' Foggy Mountain Boys, formed right after Flatt and Scruggs left Bill Monroe's band. Between 1948 and 1950, they recorded 28 songs for Mercury Records, and all 28 have now been collected on two albums, "The Mercury Sessions, Volume 1" (Rounder SS18) and "Volume 2" (Rounder SS19). Not surprisingly, Scruggs' virtuoso banjo runs through these songs like a live current, granting even the oldest ballads a spark of excitement and newness.

"Volume 1" is devoted largely to Flatt and Scruggs' last Mercury session, a marathon affair in which they hastily recorded a batch of old songs, saving their best originals for their new label, Columbia. The session produced several of their most famous performances, including "Old Salty Dog Blues," sung by fiddler Benny Sims. Also recorded was their classic version of "Roll in My Sweet Baby's Arms." Here, Scruggs' banjo flies through the song with the breakneck speed and precision that helped establish the banjo as bluegrass' signature instrument.

Scruggs' banjo is also the star of the famous "Foggy Mountain Breakdown," presented on "Volume 2." Complementing the group's instrumental verve are some superb solo vocals, duets and gospel quartets. "Volume 2" presents four songs in the brother duet style, highlighting the forceful blend of Flatt's casual lead vocals and the tense high harmonies of mandolinist Curly Seckler. One of the best gospel quartets here, the uptempo "God Loves His Children," adds the keening high tenor of Mac Wiseman. There is also a delightful hillbilly blues, "Doing My Time," where Flatt's voice trails off in a bluesy cry, reminiscent of Jimmie Rodgers.

After he left the Foggy Mountain Boys, Wiseman developed a distinctive musical approach that made him one of the most commercially successful bluegrass acts of the '50s. A new collection of his Dot releases from the '50s, "Early Dot Recordings" (County CCS108), reveals a somewhat odd bluegrass sound touched by elements of pop and western swing, especially the use of twin fiddles. Unlike other bluegrass acts, Wiseman consistently emphasized his vocals at the expense of the instrumental support. Even on standards like "Love Letters in the Sand," Wiseman's highly mannered and sentimental singing gives his material an archaic feel.

Like Wiseman and Flatt and Scruggs, Jim and Jesse McReynolds were bluegrass pioneers. They married the older brother harmony style of duos like the Louvin Brothers to the new instrumental dynamism of bluegrass. Some of their earliest Capital releases, collected on "Air Mail Special: Early Recordings 1952-1955" (Rebel 851), still carried the precious, ingenuous air of '30s recordings by the Blue Sky Boys or Delmore Brothers. Others, however, like the driving "Air Mail Special," emphasized Jesse McReynolds' unique cross-picked mandolin style, which created a rolling stream of notes reminiscent of the banjo.

There's no doubt that Jim and Jesse's success as the longest performing brother duet in country history is largely owed to their outstanding high harmonies. Because Jim's tenor harmony was softer than other bluegrass singers, their duets retained a smooth, light quality. In the early '60s, teamed with fiddler Jim Buchanan and banjoist Allen Shelton, Jim and Jesse recorded probably the finest bluegrass of their career for Epic records.

"The Epic Bluegrass Hits" (Rounder SS20) is a superb collection of Jim and Jesse's bluegrass treatments of older brother duet numbers, folk songs and traditional country. From the ethereal "Dreaming and Drifting of You" to the social protest of "Cotton Mill Man," the band shows a remarkable versatility and imagination. However, by 1964 the group was teamed with producer Billy Sherill and, as "It's a Long Long Way" reflects, they began to pursue a more commercial and conventional country sound.