This 1997 Sony edition of The Notorious Byrd Brothers contains additional material, tacked on to the last track (17). After a few seconds pause, we hear an attempt to record a number for which Michael Clarke either cannot or won't play what McGuinn, Crosby, and producer Gary Usher suggest would be appropriate: a jazz shuffle rhythm and relevant turns to accent different sections of the song. The crew are variously encouraging of Clarke, Usher especially, but the drummer seemingly hates the material and, perhaps, his inability to provide what's required.
At one point Crosby and McGuinn have a mild go at each over the other's ego, but, basically they seem to have a shared vision of what they want to accomplish. This studio chatter is instructive and no doubt is representative of any of that era's rock bands' toil to create something fresh in the studio.
If this is also included in the Byrds' boxed set, perhaps someone can mention it.
It would've been a nice touch if Sony had told us which tracks featured subsitute drummer Jim Gordon.