The first time I heard "Taxman" was also the first time I recall recognizing the bass guitar as something other than what was at the bottom, keeping a song whole. I thought McCartney's distinctive phrase on the intro was as important to that song as Harrison's guitar solo, except it wasn't Harrison. That ferocious guitar solo that happens twice is also Paul, and believe it or not, I only found that news out in the late 90s. I hung my head.
Then, just under a year ago, I was mildly embarrassed again, when I credited one of my favorite drum parts to one of of my favorite drummers. I was having a "Rag Mama Rag"/Levon Helm moment, only to be told, "That's Richard Manuel." This incident might have actually happened on these premises.
Hey, it happens!
Are there more songs featuring surprisingly amazing and distinctive parts not played by the starting player of the instrument?
Any one man band artists like Todd Rundgren, or McCartney on his solo records, should not be considered. I'm looking for obvious songs by obvious bands, like if we found out the guitar solo on "Stairway To Heaven" was John Paul Jones.