The digital world has added many new wrinkles to the music landscape, the latest being the immediate availability of sought-after vintage and long out-of-print works.

The digital world has added many new wrinkles to the music landscape, the latest being the immediate availability of sought-after vintage and long out-of-print works. The catalogs of Cambridge, Mass.-based Rounder Records and Memphis' venerable Sun Records labels are two such examples, with virtual vaults being thrown open for collectors and aficionados.

The Rounder Archive Series will launch May 31 via Rounderarchive.com with access to a treasure trove of roots music and select new releases. Ten to 15 titles will be made available quarterly as downloadable digital files and as limited-edition CDs. Accompanying liner notes, photos and album art will be available as Adobe PDF files either as downloads or as files on the CDs themselves.

"There's so much great music that's either out-of-print or that never makes it to the marketplace," Rounder VP of A&R Scott Billington says. "By offering several ways to buy this music, and by providing the accompanying notes in an easy-to-access format, we're able to offer a complete experience for our customers, who are among the most enthusiastic music fans in the world."

The first installment of Rounder releases includes music by Vassar Clements, Clark Kessinger, Fred Price and Clint Howard, Happy and Artie Traum, the Reverend Pearly Brown and the Nashville Jug Band.

Today (May 19), Sun launched its venture with subscription music service eMusic, offering more than 400 tracks from such legends as Johnny Cash, Jerry Lee Lewis, Roy Orbison, Carl Perkins, Howlin' Wolf, Sonny Burgess, Little Milton and Rufus Thomas. The tracks are arranged as 18 custom compilations.

Over the next few months, more than 1,500 "national treasures," as eMusic COO David Pakman calls the Sun catalog, will be made available. Recorded between 1950 and 1966, many of the songs have been out-of-print (some only ever released on vinyl) or found on box sets. "This is a huge win for our subscribers," Pakman adds.

Additionally, eMusic has also licensed rights to 5,000 tracks from the Sun Entertainment Corporation catalog, which includes the Red Bird Records, Blue Cat Records, Plantation Records, SSS International, Jessup Records, Silver Fox and Amazon labels. Among those gems are recordings by Floyd Cramer, Johnny Horton, Sleepy LaBeef, Ike Turner and the Kings of Rhythm, Floyd Tillman and Harold Jenkins, who was later known as Conway Twitty.