Big bands I love em’ --- I played guitar with a senior band here in Florida. The leader would allow me to take the band arrangements home so that I could used them to create a sequence on my keyboard.
Drummer???

Every time someone recorded my group the drummer cut through the other instruments. That’s why they place microphones in different areas so that they could be adjusted by a mixer. In church they place a drummer in an enclosure with headphones. Why? You heard the drummer out front and it did not sound very good. If you were there listen to the big band, under the same conditions it would sound different.

I have always believed that: The bass is the heart of the group and the drummer sets and holds the beat.
I had a 4 and sometimes 5, piece group. I told the drummer to hold the beat no matter what my guitar was doing. In reality I was playing on top of the beat (just before it) giving the song we were playing a lift. You would not try to measure the difference; it was more like a feel. Same thing when we played a ballad; I played behind the beat forcing the beat to drag – but the drummer held the beat.

Only my opinion.
Oh how I miss those days, John C.

PS, the best senior band I have ever heard here in Florida was The Second Time around. Fantastic.