Below is a paragraph in a short story where the wife tells (humorously) about how she has been sharing a bed with her husband Rick for many years. She uses a figurative language and I cannot understand it. Can you please retell it in plain English, replacing all words in the figurative sense with words in the literal sense?

"As bedmates, we've played the classics, experienced arpeggios, found dissonance, kept playing and discovered it was worth it: the sour notes resolve a few bars later. During years 3 to 7, tiny little grace notes snuggled between us for night feedings. During those years, I repeatedly pounded Rick awake, demanding to know if one of us had squashed the baby.
In later years, when the grace notes became quarter notes, the bogeyman took to calling. Many nights our bed became a fortress, our bodies the walls, and between them a child at peace."

Please help.

Okay, here goes:

As bedmates/sex partners, we've done the stuff that is normal, and tried a few things that were exciting. Sometimes it wasn't so great, but we didn't stop trying, and it was worth it. Things that didn't work very well worked out in the end.

After they had been married for three years (and for the next four years), their children, as infants, would come to bed with them. When the infants became older children, they were afriad of the bogeyman (an imaginary scary person), so their bed became a place that their children felt safe.
Thanks Grammar Geek for your help.