Think of music as a language. Language has phonetics, tempo, rhythm. If you have trouble understanding someone speaking your own language who has an "accent", then subtle variations in the above properties of language throw you off.
Same is true in music. Rhythm is one of several characteristics of music that allow us to "understand" it. A steady, regular beat is pleasurable to most ears. 4/4 (2/4) and 3/4 (6/8) time are quite common and listeners can follow it, tap their foot or snap their finger in time with the music.
Anything outside of these rhythm structures is quite difficult to understand and follow. Not that they wouldn't be interesting, just different from normal conventions of music.
Ultimately, rhythm is the mathematics behind music. Beautiful music is beautiful math!
See for your self: Play a song, your favorite song, something that you know all the lyrics and melody too. Sing the song as best you can. At the same time tune your radio onto another song, different beat, turn the volumn up a tad higher. It will be hard to stay on the melody of the song you are singing since the rhythm is different. Try singing any song and tap your hands to another rhythm it just doesn't sound right. Rhythm is what makes the song flow.
My rhythm has certainly changed in the last year, I now wear a partial plate to replace some missing teeth which I do not like because I cannot chew gum. Gum is important to me because due to new meds my mouth gets dry a lot. These new meds are to help my heart stay healthy since it had three blocked arteries, two of which now can boast of bypasses. I take a ton more medicine to keep blockage from happening again. Also I now wear hearing aids...plus a knee brace since I need a knee replacement. On top of that I use a cane to keep me from falling till I get the knee replacement. Yep, my rhythm has changed a lot. One thing is sure, I am appreciating the "rests" that is inserted in the rhythm of my life much more than I ever did.
A metronome is a device that produces an audible beat—a click or other sound—at regular intervals that the user can set in beats per minute. When God is the metronome of my life His steady beat will calm my mind and there will be a peace despite whatever the rhythm of life brings my way. I am learning to released unrealistic expectations, seize opportunities, anticipated what's next and paced myself. Keeping eternity in view as I adjust to this new rhythm makes all the "new" worthwhile.
This is a prayer of Solomon
“May God . . . keep us centered and devoted to him, following the life path he has cleared, watching the signposts, walking at the pace and rhythms he laid down” I Kings 8:56-61