The best opening act you've ever seen & heard?

John Prine opened for Pat Metheny. John was solo. It was Metheny's First Circle tour. Santana opened for the Dead at Mile Hi in 91. AC/DC opened for Aerosmith in 77.  Some good shows. My favorite Little Feat opened for Jimmy Buffet in 88 at Fiddlers Green. Fantastic.

Several great concerts! Mine are:

Johnny Winter opening for Rod Stewart & the Faces opening for 3 Dog Night. 1969 Olympia in Detroit. My first major concert!

Another for Stevie Wonder opening for the Stones. They jammed together at the end. 1972 Cobo Hall Detroit. People without tickets broke down the doors trying to get in… only in Detroit!

Santana opening for Clapton. They jammed together at the end. 1973 Cobo Hall Detroit. Fantastic!

Mine is the same as Skippytate- Van Halen opening for Black Sabbath at MSG in 1978 (not 1980 like vinyl shadow mentioned) Ozzy had already left by 1980. In fact, his first tour was opened by Def Leppard which might get an honorable mention in this category. 
 

VH had just released their first album and my friends and I loved the album and loved the show. However, at MSG anyhow, the Sabbath fans were rabid. And by the end of the set they were more than ready for Van Halen to get off the stage. It was an incredible show. So glad I got to see Ozzy with Sabbath. 

Well, there was this dive bar in Berkeley and Quicksilver was headlining. It was the bad Quicksilver, Dino Valenti posing and Cippolina long gone but we went anyway. The opening act was this bunch of High School kids. Really, 16 and 17 year old gals. We all liked the blonde bass player. we had never heard of the Runaways.

You should have seen the groupies. All guys...

That show in Oakland where the Dead opened for the Who, we were right up front and we were yelling at the Dead from the start to tune up. After a bit they stopped and started talking about how the guys in front were yelling at them so they tuned up. They were really good after they got that out of the way.

Mott the Hoople at Winterland. Second on the bill was BTO. We couldn't stop laughing at the. It was like having three fat bass players on stage at the same time. The opening act was a bunch of kids that seemed more interested in shaking their behinds than playing music. We couldn't hoot them off the stage quickly enough. That was Aerosmith. Man they were lame.

Then there was Doc Watson at Stanford. The opening act was John Fahey. John came out on stage alone with a chair and a guitar and a bottle of Burbon. That's it. He tore it up.

Thw Who at the Cow Palace, the kick off of the Quadrophenia tour, the night that Moon only played half the set and had to be carried off and they got a kid out of the audience to play drums for the second half of the show, that night? The opening band was a complete unknown, Lynrd Skynrd before all the guys were dead. They were at their best when they were alive.

I won't even mention the Go Go's opening for AC DC.  They were fun. Then again, the Dead Kennedy's opening for the Clash at Kezar Pavilion was great. The floor there is on springs. It's really a Basketball arena. Great but small. They had the stage set up on the floor of course with all those overhead lights. When the crowd commenced to pogo the floor went up and down on the springs and the lights went up and down over their heads. 

They had to stop the show to pull the lights down.

After that drama the Kennedy's continued followed by the Cramps and the Clash. The real star was the floor.

Sometimes the very best opening act is no act at all. Saw Ray Charles a couple of times at the Great American Music Hall which holds only a few hundred and there was no opening act. Ray and his band came out and did their thing.

That was just fine with me.

In the seventies, Earl Klugh (who I never heard of at the time) opened for Bob James.

After the concert, the record store was still open, so I bought every Earl Klugh album they had.

His live performances are WAY better than his studio work (which still ain’t shabby!)

A few years back Ledisi opened for Gregory Porter. She was excellent! Funny, warm and told some fun stories. Since I had a VIP package my wife and I posed with her and got some nice pictures (when I posed with her she looked at my wife and said, “Don’t worry. I’ll give him back when I’m through!” She was very sweet and funny!