by Zac JohnsonWith its feet in the most traditional of American folk music and its head peeking through a cloud of psychedelic hippie smoke, John Hartford's 1971 LP, Aereo-Plain, was groundbreaking in its ability to sound earnestly faithful to the music it was rooted in, while still twisting words and poking fun in a way that was definitely hip for the time. The informal jam session feel of the recordings created some 80-odd reels of tape that couldn't all fit onto the LP, so in early 2002 Rounder Records' impeccable Select division released Steam Powered Aereo-Takes, featuring nearly an hour of song sketches, outtakes, demos, impromptu jams, and goofing-off suites. All the members of the assembled team -- including Hartford on guitar, banjo, and vocals, Norman Blake on guitar and mandolin, Tut Taylor on dobro, mandolin, and mandola, Vassar Clements on fiddle and mandocello, and Randy Scruggs on electric bass -- were at the top of their musical game in the early '70s, and the recordings show it beautifully. If the sessions that were used on Aereo-Plain became the Revolver of the progressive bluegrass movement, this disc is more like the White Album or maybe Let It Be. The song ideas are there, but they feel looser and more free, with each of the performers playing with ideas and song structures, fiddling with things when they don't work, and milking them when they click.