This morning I heard it in front of the Bascom House then got on it a short while later out in the open on a path in the Wildflower Garden where it sang constantly. The path was near the beginning of the Garden and on the side closest to the field. I used my birdpod to id the strange song. I could tell it's small size because it was standing next to a song sparrow for part of the time. There were song, lincoln, chipping, white-throated and field sparrows all over. Very few warblers in the Wildflower Garden and immediate area.