in the pocket

I've never thought that the groove was the beat; I always saw it as the space between the beats. I believe that's where the phrase "in the pocket" originated.

2013, Loren Weisman, The Artist's Guide to Success in the Music Business, page 229

Musicians who play funk and Latin tunes refer to the groove as the sense of being "in the pocket," while jazz players refer to the groove as the sense that a song is really "cooking" or "swinging"... Historically speaking, the term pocket originated in the middle of the previous century, when a strong backbeat (the snare drum striking on beats 2 and 4) became predominant in popular music... Many people feel that the question is not so much what the pocket is as much as how you know when you're in it; I guarantee that you'll know it when you feel it, because the music feels as though it's playing itself. It feels as though everything has merged together, with all the rhythmic parts being played by one instrument.

2016, Bobby Owsinski, The Music Producer's Handbook, 2nd edition

Use his approach for both songs to keep your rhythms in the pocket. You needn't be rigid; some stretching of the phrase is absolutely allowable for the sake of meaning. For the most part, however, ride the driving pulsations of the accompaniment with an equally grooving vocal approach.

2019, Joseph Church, Rock in the Musical Theatre, page 173

...Iyer argues that the backbeat in much postwar African-American popular music is seldom precisely on the beat: it is slightly delayed, lending it a more 'laid back' feel. Again, as with swing, playing the backbeat 'in the pocket'—just slightly behind the beat—does not disrupt the regularity of the beat so much as demand that we hear (and feel) the rhythm in a more subtle and integrated way...

2020, Paul Thberge, “Click/Beat/Body: Thoughts on the Materiality of Time and Tempo”, in The Auditory Culture Reader, page 344

Most musicians who play classical music usually play too "stiff" (rigidly) to perform on popular music recordings. All forms of popular music require musicians to feel the groove and to play in the pocket (playing within the feel of the rhythm section).

2021, Michael Zager, Music Production, page 97