Dave Bonta's "Music lesson" is only four lines long, but it packs in a surprising idea: that music came before our usual way of measuring time. The poem calls music "the first clock," a way of marking time through rhythm and beat. This happened "before time had discourse / with arms," which seems to refer to the arms of a clock, the hands that sweep around a face. So music counted out moments before clocks existed to do it.
The last line, "A bridge in the night," shifts the picture. A bridge connects two places, and night suggests darkness or uncertainty. Music here seems to carry us across something, perhaps from one moment to the next, or through loneliness or the dark.
The speaker sounds quietly reverent, as if sharing a small discovery. The mood is calm, mysterious, and a little tender. Rather than explaining music, the poem offers a few images and lets you feel its older, deeper kind of time.