Ten thousand lead-crystal pendants dance beneath a cloud of scrunched-up chicken wire. Suspended on nine poles above a fancy patio, the art installation “Cloud Terrace” captures the stark, cold winter light and throws it back in flashes of color, intense bursts of orange, scarlet, indigo. John Beardsley has been drawn to this spectacle over and over since it went up in April and has found it to be a siren with many songs.