The Beatles, Abby Road-the entire album! In '69 if you copped the album, you could get gigs because even the guitar players struggled to get the parts down, George was no slouch. This was actually a great learning experience for a young bassist just starting out. It provided a good example of what melodic feel was kinda all about. The most memorable track that illustrated what I'm getting at is "You Never Give Me Your Money" go ahead and give it a whirl, it's pretty fun once you get it down. I-IV-V it ain't.
1965 - 1969 was a pretty heady time for young bassist's. Motown, Jimi Hendrix, Led Zeppelin, The Who, Cream, and towards the Summer of '69 and onward the prog scene started, and took us through the 70's
At the start of it, The Beatles set the bar in '63 for all that followed bringing us to where we are today.
In broader terms the Jazz & Blues greats & legends of the late '20's to the '50's and then when Rock started to take hold in the early '50's to the early '60's it was during the mid '60's that things really started to progress beyond the I-IV-V.