Long before 'jam band' entered the music lexicon, Steve Winwood encouraged his bandmates to improvise and improve on recorded versions of his songs. Even in the late '60s, Traffic, the greatest band to never have a top-40 hit, would think nothing of stretching a three-minute pop song into a 15-minute opus.
Friday night at the Orpheum, Winwood, during a riveting three-hour show, played that improv thing to the hilt. Like Bob Dylan, Winwood continues to reinvent himself and tinker with his most beloved songs. ``Low Spark of High-Heeled Boys,'' a classic Traffic track from 1971, was so long that before it ended we're sure autumn changed into winter. ``Rainmaker'' segued into War's ``Slippin' Into Darkness,'' with a bruising Junior Walker-like sax break by Jay Davidson, and then into a long free-form funky jazz riff.