By Blaine Schultz, special to   Published Jun 26, 2008 at 7:30 AM

Over the span of nearly 30 songs Wednesday night Willie Nelson demonstrated why he is an icon. Beneath a massive Lone Star flag the 75-year-old Texas troubadour played his heart out to a capacity crowd at Potawatomi's Northern Lights Theater.

From a trio of Dubuque ladies that are following him to all his Midwest shows to punk rock hipsters, Nelson's appeal crosses all boundaries.

Strumming "Trigger," his trusty and nearly worn out Martin classical guitar, Nelson opened with "Whiskey River" and never looked back. Along the way he played a medley of hits that put him on the map -- "Funny How Time Slips Away," "Crazy," "Night Life" -- tributes to heroes -- Hank Williams' "Jambalaya," "Hey, Good Lookin'," "Move It On Over" and "I Saw the Light" -- and friends -- Kris Kristofferson's "Me and Bobby McGee" and "Sunday Morning Coming Down."

Wilson was backed by his longtime Family Band which includes his sister Bobbie Nelson on grand piano and brothers Paul English on snare drum and Billy English on percussion, and which Wednesday night was augmented by the next generation, too. Nelson's sons Lukas performed on guitar and Micah on drums.

There was even room for guest guitarist Kenny Wayne Shepherd -- who performed the previous night at The Pabst -- on a few tunes.

Nelson's set list may resemble a Rorschach Test on paper, but in practice it flows like a great jukebox. "Bloody Mary Morning" displayed a drummer a two percussionists improvising off Nelsons' funky guitar riffing -- you get the impression this is the music that Deadheads always wanted to hear.

Digging below the hits with "Still is Still Moving to Me" and "Angel Flying Too Close to the Ground," Nelson also generously shared the spotlight with harmonica player Mickey Raphael and sister Bobbie for solo spot on "Pine Top Boogie."

Nelson's sons' band, 40 Points, opened the evening with a short set of tunes that balanced blues jams and classic rock with a Latin tinge. But when Lukas Nelson sang the first notes, his DNA was obvious.