A Reverie ["Did I dream of a song? or sing in a dream?"]

Did I dream of a song? or sing in a dream?     Why ask when the night only knoweth?     The night -- and the angel of sleep!     But ever since then a music deep,     Like a stream thro' a shadow-land, floweth     Under each thought of my spirit that groweth     Into the blossom and bloom of speech --     Under each fancy that cometh and goeth --     Wayward, as waves when evening breeze bloweth     Out of the sunset and into the beach.     And is it a wonder I wept to-day?     For I mused and thought, but I cannot say     If I dreamed of a song, or sang in a dream.     In the silence of sleep, and the noon of night;     And now -- even now -- 'neath the words I write,     The flush of the dream or the flow of the song --     I cannot tell which -- moves strangely along.     But why write more? I am puzzled sore:     Did I dream of a song? or sing in a dream?     Ah! hush, heart! hush! 'tis of no avail;     The words of earth are a darksome veil,     The poet weaves it with artful grace;     Lifts it off from his thoughts at times,     Lets it rustle along his rhymes,     But gathers it close, covering the face     Of ev'ry thought that must not part     From out the keeping of his heart.