Some of the music blogs I read have been reviewing assorted albums released in 1969 (and thus celebrating their 40th anniversary this year) and discussing the impact these albums have had on their lives. Despite personally having a younger vintage than these albums some of them did have a rather strong impact on me.
Some of the better albums released that year:
The Beatles Abbey Road
Chicago Transit Authority s/t
The Sons of Champlin Loosen Up Naturally
King Crimson In the Court of the Crimson King
Led Zeppelin II
Quicksilver Messenger Service Happy Trails (live)
Doors The Soft Parade
The Rolling Stones Let It Bleed
Blood Sweat & Tears s/t
The Who Tommy
Boz Scaggs s/t (incidentally this one makes the list largely due to the Duane Allman guitar solo on Loan Me a Dime)
I've only reviewed 2 from the list (follow the links if interested) but those 2 albums have a lot in common:
Both the Sons of Champlin & Chicago:
had guitarists named Terry (Kath in Chicago, Haggerty in the Sons of Champlin)
had 7 members
had a 3 piece horn section
had double LP debut albums
had debut albums released on the exact same day
at one point or other in their history featured Bill Champlin on lead vocals, keyboards, and sometimes guitar.
and... admittedly this last one is a bit of a stretch. The last song on Chicago's debut is the 14+ minute Liberation. The last song on the Sons of Champlin's debut is the 14+ minute Freedom.
As a teenager I listened to both of their debut albums incessantly. I just couldn't get enough. The music was and still is excellent. And it never fails, I'm always able to hear something "new" that I didn't notice on previous listens.
It was the musical adventurousness, innovation, and overall inventiveness of these bands that opened my ears, heart, and mind to a lot of other great music of the same era.