OMG...quite a few...
Bootsy Collins WAY before he got fame - I hitchhiked about 80 miles to a gig at a college in Ohio where I was one of maybe a half-dozen palefaces in the crowd. Lately he's watered down his act and all you see in the audience is Whites. LOL
The incomparable (and closeted) Russian pianist Vladimir Horowitz during what turned out to be his last tour.
Peter Tosh at a crammed club during what also turned out to be his last tour. The man sparked a spliff on stage that had to be three feet long.
Everybody in the place got a contact high if they weren't blazing already. And the band was on fire.
Stevie Ray Vaughan - twice. RIP
James Cotton, Ronnie Law, and Third World at the now discontinued UMass-Amherst springtime "Pond Concert."
The demonically possessed Itzhak Perlman at Cincinnati's architectural masterpiece Music Hall.
Yes - with Jon Anderson but without Rick Wakeman - on the Boston waterfront. Sixth row center.
Page/Plant in 1995, one of the first shows in what's now called the TD Garden in Boston. They brought in a full symphony orchestra for "Kashmir." Jimmy Page plucked some North African instruments during a few songs. Robert Plant managed a few screams like the old days. Zep maniac heaven.
More recently: The yet to be discovered jazz a cappella group Vox One. Mind-blowing what can be done with the human voice.
And the all-"girl" cover band "Lez Zeppelin," who tore the place UP.