My very first concert (I was thirteen) was on Friday August 16th 1974, at the Capital Centre in Landover Maryland. It was a happy accident, as one of family friends had a cancellation.
If memory serves me correctly The Souther/Hillman/Fury band opened up, second was Little Feat, and the headliner was Three Dog Night (though I could have the first two bands backwards). Went with an older friend and her boyfriend, his sister and brother.....they were all huge Three Dog Night fans.
I remember really really really liking Souther/Hillman/Fury, and absolutely having my face blown off by Little Feat; and actually Three Dog Night was excellent too. To this day Little Feat Waiting for Columbus is my favorite album of all time, it brings back memories of that night.
Souther/Hillman/Fury also led me to bands like Poco, Manassas, Buffalo Springfield, and CSN&Y in all of their iterations. Funny how a twist of fate can change your life. I have spent the last decade trying to find a concert poster of that night