A few random, non-sequential thoughts and opinions, if y'all will indulge me...
I found myself nodding my head in agreement with more than several of the previous posters, particularly Skip, Steve Hinson, Jack Wilson, and Jeff Neal.
To me, more important than a precise tempo is "groove," which is the combination of all of the band having a general agreement of how a song should flow; seamlessly, and without argument between the players. The tempo during a song may vary +/- a few bpm but if everyone agrees to it, there's a natural groove happening and all is cool. It's hard to define specifically, but the listener and dancers know it when they hear it.
Occasionally, a really proficient but metronomic drummer can keep a band from grooving; if the player/singer calls off a tempo too fast or slow, an unfamiliar but metronomic drummer, such as a fill-in or sit-in situation, can keep the uncomfortable tempo for the entire song. Much to the dismay of the band.
Re: a song should "breathe." IMHO, a big problem with a 4/4
country shuffle such as a Price/Faron/Bush song is a drummer too in love with his kick drum. To get that sound correct, the bassist carries the 4 beats to a measure simply with a triadic line, and the drummer plays the kick on beat 1 and 3 while the snare plays on 2 and 4. The piano left hand plays the same line as the bass, and the right hand plays the chord changes on the off-beat. The acoustic rhythm guitar gently and unobtrusively plays 1 and 3 on the downstroke and 2 and 4 with the upstroke. No guitar runs on the bass strings, unless it's tic-tac on the electric guitar.
IMHO, that's the ideal shuffle configuration. This depends on a strong bassist, drummer, and keyboardist who are
disciplined enough to play it that way. For me, drummer hammering the kick drum with great force on every beat is like trying to sing or solo having two hands around your neck while gently being strangled.
I enjoy a drummer who knows when to groove and when to be metronomic, such as when an arrangement goes from 2/4 to 4/4 and then back (or not). Often tempo will noticeably speed up when going to 4/4 due to an overly enthusiastic bassist or lead player. For me, if a band groove can still be held when the time signature goes from 2 to 4, that's a disciplined rhythm section. Listen, if you will, to the
Western Strings album by the Cherokee Cowboys as a perfect example of what I'm opining about. "Rubber Dolly" comes to mind; it's all in that performance.
My rig: Infinity and Telonics.
Son, we live in a world with walls, and those walls have to be guarded by men with steel guitars. Who's gonna do it? You? You, Lt. Weinberg?