Explaining to a non-musician what it means to play beats I compared it to a fixation with right angles: everything has to line up nice and tidy with an identifiable beat.
If I hear more than, say, three of such beats in a row I am almost certainly going to lose interest. All kinds of things can occur to enliven beats: little things like unpredictable accentuation, or no accentuation at all; and bigger things like groupings of three within a 4/4 meter.
I am appalled at the amount of square playing I hear when I tune into the classical music station at random. How thrilling, on the other hand, to hear something that is the opposite of square.
Two performances I heard yesterday qualify for that: Stephen Hough playing the Grieg Piano Concerto, which squares maintain is an uninteresting piece - boy are they missing something!
Gustav Dudamel conducting those famous Dances from Borodin's Prince Igor, in a live performance with the Berlin Philharmonic.