Correction: Derek Trucks, who performed Friday night at Jefferson Center, had a glass slide on his left hand. That fact was incorrect in Saturday’s review of the show, in print and online. Online versions have been changed.

The great majority of guitarists spend their entire lives trying to develop a voice on their instruments. At 29, Derek Trucks has long had his.

With a Gibson SG electric strapped on, a glass slide on his right ring finger and the thumb, forefinger and middle finger of his right hand — no pick required — Trucks produces a tone and legato that is as close as a guitarist gets to emulating the human voice, without a rack of effects at his feet.

It’s what drew more than 900 people to a sold-out Jefferson Center on Friday night. He and his Derek Trucks Band gave it to them over the course of about two hours, playing tunes that ranged from gut-bucket blues to rock-god madness to what one could call American raga. Many responded as though they’d been hypnotized.

It’s not even what Trucks does best.

One day, if he chooses, Trucks will set new standards in modal, even free-form, playing. He showed that potential over some 10 minutes Friday, in a conversion of the English traditional folk song “Greensleeves” to jazz. Sans slide, he took it about as far outside the box as an average listener could imagine it going, while still implying the ancient melody through layers of jazz wildness, as the band swung hard behind him.

But Trucks is a man of soulful and funky roots. His five bandmates — personnel largely unchanged over the past decade — are with him as one. Keyboard and flute player Kofi Burbridge at times approached Trucks’ brilliance. Mike Mattison’s silk-to-sandpaper vocals were perfect for such originals as “I Wish I Knew (How It Would Feel to be Free),” the bluesy new number “Already Free,” and the encore cover song “Freddie’s Dead.”

Drummer Yonrico Scott, bassist Todd Smallie and percussionist Count M’Butu are great partners in the rhythms for such songs as “Sahib Teri Bandi-Maki Madni” — an Indian classical music-inspired wonder of dynamic and tempo control in which Trucks shows another path he could take to arrive at guitar immortality. He hasn’t got far to go.

Opening act Joe Pug was folky, engaging, a good fingerpicker, and largely forgotten by the time Trucks and his band left the stage.