There is a review of a Bob Dylan/Merle Haggard in the New York Times:
It's some kind of career milestone when musicians start acting older than they are, rather than younger. Both Bob Dylan, 63, and Merle Haggard, the 68-year-old country patriarch sharing his tour, reached that point long ago, seizing the chance to be avuncular, cranky and committed to traditions they see disappearing.
Wearing matching suits, Mr. Dylan's band looks like a 1940's country act; Mr. Haggard's band, the Strangers, sometimes plays like one. But the wrinkles and antique trappings shouldn't fool anyone: these two songwriters are as sharp and rigorous as ever. They performed Tuesday night at the New Jersey Performing Arts Center here, and they start a five-night stand at the Beacon Theater in Manhattan on Monday night.
...Mr. Dylan played electric piano, using quick chord jabs to spur the music, or stepped to center stage for pointed, melodic harmonica solos. His voice was in a thick, raspy phase, but when he wanted to sound most menacing, he would ease back into a sardonic croon, as he did when God threatened Abraham in "Highway 61 Revisited."
...Mr. Haggard has slyly backdated his music: from the swinging, twanging Bakersfield style of his 1960's and 70's hits to an invented old-time country that embraces fiddle tunes, western swing, yakety saxophone and pop standards along with drinking songs. His band is almost dainty in its well-oiled swing, as it dips into blues or New Orleans jazz, country waltzes or the Nat Cole hit "Unforgettable."
I really love that Bob Dylan plays the electric piano now. I can't think his playing an instrument that would disappoint his fans more. French horn, maybe.